Arrakis
The planet known as Dune. The governorship of Arrakis is complex because it's the only source of spice in the known universe, which makes it very important and profitable; however, Arrakis is a desert planet, inhospitable to human life. The Duke Leto Atreides is given control of Arrakis at the start of the novel, and he takes his House, including Paul, to the historical capital city of Arrakeen.
Bene Gesserit
The exclusively female ancient school of mental and physical training, established thousands of years ago. Those with Bene Gesserit training can have a variety of powers, from body control to truthsaying to using the Voice. The Bene Gesserit have controlled human politics for centuries, determining which bloodlines have mixed over the last 90 generations. They hope to produce the Kwisatz Haderach. Lady Jessica is a Bene Gesserit, and she gives Paul some Bene Gesserit training.
CHOAM
An acronym for Combine Honnete Ober Advancer Mercantiles. The CHOAM Company is the universal development corporation, meaning they essentially control economic affairs across the universe; however, the Guild controls space travel, so CHOAM relies heavily on the Guild. Shares in the CHOAM Company are desirable. As Irulan's dowry at the end of the novel, Paul demands all of the Emperor's shares, basically leaving him destitute.
crysknife
A knife made from the tooth of a sandworm. A crysknife is sacred to the Fremen on Arrakis.
Fremen
The "native" population of Arrakis. Actually remnants of the Zensunni Wanderers, persecuted across many planets before finding a home in the deserts of Dune. The Fremen are fierce and controlled warriors, protective of their tribes and distrustful of outsiders. Thanks to the intervention of planetologists like Dr. Kynes and his father, the Fremen work toward a generations-long goal of making the surface of Arrakis a paradise. Fremen all have purely blue eyes due to the natural spice diet of living on Arrakis.
Fremkit
A desert survival kit made by Fremen. Usually includes tools like a stilltent (a water-saving tent for surviving the harsh daylight), a thumper (a device to distract sandworms), and a paracompass (the only kind that works on Arrakis). Used in combination with a stillsuit, which recycles a body's water, a Fremkit allows for survival on Arrakis.
gom jabbar
A poisoned needle, particularly one used by the Bene Gesserit to test human awareness and impulse control. The Reverend Mother uses the gom jabbar to test Paul at the beginning of the novel.
the Guild
The Spacing Guild is one of the three legs of the known universe's political structure (the others being the Emperor and the Landsraad). The Guild has a monopoly over space travel, because they alone can use spice to determine safe pathways through space.
kanly
Kanly is a formal feud or vendetta carried out under strict conventional rules. Duke Leto Atreides uses the word "kanly" to describe his relationship to the Baron Harkonnen at the beginning of the novel, and at the end, Feyd-Rautha Harkonnen uses that same kanly as a reason to fight Paul to the death.
Kwisatz Haderach
Literally "Shortening of the Way." The Bene Gesserit have been selectively breeding bloodlines for 90 generations to produce the Kwisatz Haderach, a male Bene Gesserit whose mental powers would bridge space and time, allowing sight into the past and future in both masculine and feminine directions. Paul Atreides is the Kwisatz Haderach at the end of the novel.
Lisan al-Gaib
Literally "The Voice from the Outer World," sometimes translated as "Giver of Water." Fremen legends tell of an offworld prophet who will guide them in their path toward making Arrakis a paradise. The Fremen decide that Paul is the Lisan al-Gaib.
melange (spice)
The geriatric spice, melange, can only be found on Arrakis (in this novel). Spice prolongs youth and is addictive, and it turns eyes purely blue. Paul-Muad'Dib and Guild navigators all use spice to increase awareness and "see" across space and time.
Mentat
Human beings trained to become "human computers," capable of supreme accomplishments of logic. The more correct information a Mentat is given, the more accurately the Mentat can predict the future. Thufir Hawat is Mentat to House Atreides, and later House Harkonnen; Piter de Vries is Mentat to House Harkonnen before him. Mentats tend to have red-dyed lips from taking sapho juice, which increases their abilities.
Missionaria Protectiva
An arm of the Bene Gesserit order that spreads superstitions and religious fervor on primitive worlds. Thanks to the Missionaria Protectiva, Lady Jessica is able to guess which words/behaviors will ensure her safety on Arrakis; the Missionaria Protectiva prepared the way for Paul to become a messiah to the Fremen. Beliefs like "Lisan al-Gaib" were planted by the Bene Gesserit centuries before the novel, just in case any sister of the Bene Gesserit arrived and needed to use them.
muad'dib
The muad'dib is a small mouse native to the deserts of Arrakis, admired by Fremen for its survival skills. When he's accepted by the Fremen, Paul chooses to be named after this animal without knowing its name, accidentally fulfilling part of the prophecy about him: he becomes Paul-Muad'Dib.
Reverend Mother
Term for a Bene Gesserit who has transformed an "illuminating poison" within her body, increasing her awareness and powers. The Fremen also use this term to describe their female religious leaders, who transform the Water of Life from poison into safety (the term is the same thanks to the Missionaria Protectiva).
Sardaukar
The soldiers of the Padishah Emperor. They are incredibly brutal and efficient fighters, rivaled by very few in the cosmos. In Dune, it's revealed that Sardaukar are secretly raised and trained on Salusa Secundus, the Emperor's harsh prison planet; the Emperor fears Arrakis will become a training ground for an equally strong rival military force.
shai-hulud
Sandworms native to Arrakis, also called "makers" by Fremen. They are territorial animals. They can grow to be longer than 400 meters (Paul rides one longer than any seen before), have enormous teeth, and are very sensitive to sound and movement in the desert. When capitalized, Shai-Hulud refers to a Fremen deity.
the Voice
A skill developed through Bene Gesserit training that allows the user to control others using pitch and tone shadings. Thanks to Jessica's training, Paul becomes adept in using the Voice.
Water of Life
The Fremen "illuminating poison" used to create Reverend Mothers. Water of Life is the liquid exhaled by a sandworm that has been drowned. It's very poisonous, and even when a Reverend Mother makes it drinkable, it's a narcotic enjoyed by the entire sietch to increase their awareness in a "sietch tau orgy" (everyone is more sensitive to everyone else's awareness). Paul drinks one drop of the Water of Life and survives, becoming the Kwisatz Haderach.
