GNK power droids were effectively power
generators with legs and simple artificial
intelligence so they could understand
rudimentary commands. They were most
commonly found on under-developed
worlds that did not have an expansive
power grid, or in mobile military
operations.

They often made a low honking noise
that
sounded like the word "gonk," resulting in
the nickname gonk droid or simply gonk.
This form of droidspeak was referred to
as
"Gonkian."-
Source:http://starwars.wikia.com/wiki/G
NK
_power_droid