droid n.

"automaton resembling a human being in form and movement," 1837, in early use often in reference to automated chess players, from Modern Latin androides (itself attested as a Latin word in English from 1727), from Greek andro- "man" (from PIE root *ner- (2) "man") + -eides "form, shape" (see -oid). Greek androdes meant "like a man, manly;" compare also Greek andrias "image of a man, statue." Listed as "rare" in OED 1st edition (1879), popularized from c. 1950 by science fiction writers.

in the internet sense, c. 2000, short for robot. Modern use has coincidental affinities with earlier uses, such as "parasitical worm or maggot" (1520s), which is of unknown origin; and Australian-New Zealand slang "worthless, troublesome person" (World War I-era). The method of minting new slang by clipping the heads off words does not seem to be old or widespread in English. Examples (za from pizza, zels from pretzels, rents from parents) are American English student or teen slang and seem to date back no further than late 1960s. Also compare borg, droid.