‘Dune’ Terminology 101: An Essential Glossary for the Uninitiated

Prepare for Denis Villeneuve's new movie adaptation with this handy vocab lesson.

This glossary of the important terminology in the world of Dune is part of our ongoing press coverage of the Toronto International Film Festival. From reviews to interviews to recap lists, follow along for all things TIFF 2021.

When news first broke that Denis Villeneuve was making Dune, I clicked my heels together like an old-timey chimney sweep. A big-budgeted, 21st-century adaptation of Frank Herbert’s seminal sci-fi novel was just too good to be true.

The idea of a good-faith Hollywood attempt to make Dune‘s whacky story digestible to average cinemagoers tickled me something fierce. While the difficulty of adapting the book is its own can of sandworms, less discussed is the problem that the world of Dune is absolutely full of invented terms that haven’t quite breached the public consciousness.

Spice? Gom jabbar? Bene Gesserit?

People who haven’t seen a frame of Star Wars vaguely understand what “the Force” is. People who have never seen an episode of Star Trek can probably recognize the phrase “beam me up” or “set phasers to stun.” Dune and its glossary of terms are far more esoteric.

Maybe you’ve heard the phrase “the spice must flow,” and maybe you know that worms and sand figure into the story, somehow. But my guess is that most viewers entering the world of Dune via Villeneuve’s movie will be flying relatively blind.

So in the interest of providing a helping hand to new, eager initiates — or anyone looking for clarity after seeing the movie — I’ve assembled a quick and major spoiler-free glossary of essential terms to understand what’s going on in Dune.

To spice things up (haha), I forced FSR’s own Anna Swanson to lend a hand. Her only familiarity with the Dune universe is David Lynch’s 1984 film. As you will see from her earnest attempts to define the glossary terms below, that adaptation of Dune taught her absolutely nothing.

The FSR Dune Glossary


Anna’s best guess: My memory tells me that this is either a planet or a mode of transportation. I’m imagining “ah-rack-us,” it’s “us,” it’s multiple people. Ergo: a planet. And if it’s a mode of transportation then it’s the “ah-rack-bus.”

What it actually is: Arrakis is the desolate, hostile desert planet on which the majority of the story takes place. It is located at the far edge of the “known universe” and is the sole source of the valuable resource known as spice melange. “Dune” is the planet’s informal name. Arrakis’ largest city, its historical seat of government, is Arrakeen. At the beginning of Dune, the Padishah Emperor — the hereditary ruler of the known universe — tasks House Atreides with assuming dominion over Arrakis.

Bene Gesserit

Anna’s best guess: It is an armor that you wear. A protective thing. It’s what you put on before you go into battle. It sounds like an item of clothing to me.

What it actually is: The Bene Gesserit are a sisterhood of women whose objective is to steer humanity towards an “enlightened” path. One of the primary ways in which they do this is through a covert breeding program. Members of the Bene Gesserit are able to control their every nerve, muscle, and breath. This mental and physical conditioning is passed down through generations and allows them to achieve seemingly impossible feats. It has earned the Bene Gesserit a reputation of being “witches” and “weirding women.”


Anna’s best guess: This is baby’s first knife. Like they christen you, and then they give you a knife.

What it actually is: A knife with a blade made from the tooth of a sandworm. Crysknives are a sacred weapon of the Fremen and cannot be sheathed until blood is drawn. Unfixed crysknives must be kept close to the human body or else they disintegrate.

drum sand

Anna’s best guess: That is a musical instrument where you bash sand until it makes a sound.

What it actually is: Anna is not far off. Drum sand is a naturally occurring phenomenon where sand emits a drum-like sound when stepped on. The resulting vibrations have the undesirable effect of attracting sandworms.


Anna’s best guess: These are people of some sort of liminal status where they are not quite free. But also not enslaved. Are there enslaved people in Dune? I feel like there are always enslaved people in these space movies.

What it actually is: Freman are the group of human beings who took up residence on Arrakis long, long ago. They now consider themselves indigenous to the planet. They are extremely skilled fighters and survivalists. And water conservation permeates every facet of their culture. The Fremen are recognized by their entirely blue eyes, a consequence of their constant consumption of spice.

Warner Bros.

gom jabbar

Anna’s best guess: I think this is a really big sword. It’s some sort of weapon. It sounds like a very important weapon. Like is it Dune‘s Excalibur?

What it actually is: The gom jabbar is a poison-tipped needle used by the Bene Gesserit in the “Gom Jabbar Test of Humanity,” a means of determining if a subject’s awareness is stronger than their instincts. If a subject is conscious of the deadly presence of the gom jabbar, which is held to their neck during the test, they will be able to resist the animal instinct to withdraw their hand from a painful device.

Kwisatz Haderach

Anna’s best guess: This is a union of two forces. Like there is the Kwisatz and the Haderach. And they were enemies that are now together. Like a merger. It’s Waystar Royco.

What it actually is: Meaning “shortening of the way” and “one who can be many places at once,” the term originates from the Bene Gesserit and describes the end-goal of the sisterhood’s breeding program: a male capable of accessing a region of prescient and genetic knowledge unattainable to women. The Kwisatz Haderach would be the amalgam of various figures all at once (“Reverend Mother,” “Mentat,” and “Guild navigator”).


Anna’s best guess: The Muad’Dib is a group of people. And they are somehow connected to the worm because the worm lives ‘Dib under the sand.

What it actually is: Muad’Dib is a rich term with multiple, intersecting meanings. Muad’Dib is the Fremen name for the desert mouse native to Arrakis. It is also the name of one of Arrakis’ twin moons. While the larger meaning of Muad’Dib is not fully revealed in the new Dune movie (a.k.a. Dune: Part One), hints at its greater purpose make it worth highlighting in this glossary. Muad’Dib is not to be confused (or is it?) with Mahdi, the name used by the Fremen to describe their messiah.

Salusa Secundus

Anna’s best guess: That is the second Salusas.

What it actually is: Salusa Secundus is an imperial prison planet that makes the physical conditions on Arrakis look like Disneyland. These harsh conditions serve as the training ground of the Sardaukar, an elite military force of the Padishah Emperor.


Anna’s best guess: I think that this is a word for someone who is young and shy. A shy hero.

What it actually is: Shai-hulud is the reverential, awe-filled Fremen term for the sandworm of Arrakis. While the sandworms are themselves a species, shai-hulud is more than a description for a physical entity (or entities). Rather, it alludes to the Fremen belief that “the sandworm” (as a concept) is the physical embodiment of powerful divinity.


Anna’s best guess: Like if you live in Rochester, New York, and you want to know what the “sitch” is. Either that or it’s a dune buggy.

What it actually is: Sietch is a Fremen term for a community or settlement. Typically located within the planet’s desolate mountains and rocky outcrops, sietches are primarily located underground. In Dune, the major Fremen sietch is “Sietch Tabr,” home to the characters Stilgar and Chani.


Anna’s best guess: Spice is the thing that the planet has as a natural resource. And it’s really valuable. It also might have magical properties. And people want it.

What it actually is: Also known as melange, spice is a powerful drug found on Arrakis. The most valued commodity in the known universe, spice grants powerful abilities, including prescience and elongated lifespans. It also allows the mutated, mentally-conditioned Guild navigators to safely navigate interstellar and galactic space without the aid of computers (there are no “thinking machines” in the world of Dune). The constant consumption of spice is what gives the Fremen their characteristic blue eyes, known as the “eyes of the ibad.”


Anna’s best guess: I think this is something that you put on and it makes you either disguised or invisible. I also think this could probably be some sort of armor. It contains the word suit so this has to be something that you wear.

What it actually is: A full-body suit worn in the open desert of Arrakis that preserves and recycles perspired moisture from its wearer’s body. The suit is designed to absorb liquids like sweat and urine and filter them into “catchpockets” to make the reclaimed water drinkable for its wearer. Stillsuits allow humans to survive in the desert for weeks. A nasal device called a “filt-plug” (bonus Dune glossary term!) captures further moisture.


Anna’s best guess: Well it’s got to be something weird. The Voice, I think is like the Force from Star Wars. Like Chalamet is trying to figure out who he is by tapping into the Voice. It calls to the hero.

What it actually is: One of the most impressive physical feats of the Bene Gesserit, the Voice is a physical technique that allows practitioners to control and compel others merely by using the right vocal tone. To the outside observer, the Voice has the appearance of mind control when it is, effectively, like using your “dog training” voice on someone and it working.

Meg Shields: Based in the Pacific North West, Meg enjoys long scrambles on cliff faces and cozying up with a good piece of 1960s eurotrash. As a senior contributor at FSR, Meg's objective is to spread the good word about the best of sleaze, genre, and practical effects.