Geonosian was the language of the Geonosian species native to Geonosis. It consisted of click consonants, possible through the dual-mandibles of Geonosians—one moving vertically, and a second, internal set moving horizontally.
Aristocrat Geonosians were also able to understand Basic fluently, unlike the lesser castes. It is unknown if they were all physically unable to speak Basic (much like Wookiees), or if they simply preferred their own language. The Queen Karina was known to be capable of speaking Basic. An off-world Geonosian, Tookra could also speak Basic.
The language was mostly spoken by Geonosians, but there have been instances of offworlders understanding Geonosian without the immediate need of a translator- Count Dooku, Shu Mai, Senator Padmé Amidala and Ysanne Isard are notable examples. Marmio Mio also learned the language while on the planet.
It should be noted, however, that the human voice-chords were apparently capable of reproducing the Geonosian sounds. Infected clones were able to reproduce the sound fairly simply and authentically. 
Behind the scenesEdit
In a Hyperspace online chat, Matthew Wood said that the sound of the Geonosians was one of the weirdest he had ever recorded for a Star Wars movie. It consisted of a penguin mating call as well as fruit bats fighting over a banana.
In Attack of the Clones, when Anakin, Obi-Wan, and Padmé are taken into the Geonosian execution arena to be killed, the Geonosians in the arena make noises that sound like Human cheering instead of Geonosian-sounding noises, even though about everyone in the arena is a Geonosian with the exceptions of Count Dooku, Jango Fett, Boba Fett, Nute Gunray, Rune Haako, Anakin Skywalker, Obi-Wan Kenobi and Padmé Amidala.
- Star Wars Episode II: Attack of the Clones (First appearance)
- "Death in the Catacombs"—Star Wars Insider 79
- Star Wars: The Clone Wars – "Senate Spy"
- Star Wars: The Clone Wars – "Landing at Point Rain"
- Star Wars: The Clone Wars – "Weapons Factory"
- Star Wars: The Clone Wars – "Legacy of Terror"
- Star Wars: The Clone Wars – "Brain Invaders"
- "The Droid Deception"—Star Wars: The Clone Wars Comic UK 6.4
- Labyrinth of Evil
- Star Wars Episode III: Revenge of the Sith
- Star Wars Episode III: Revenge of the Sith game