RhymeZone: greeble definitions

Definitions of greeble:

noun: A small piece of detailing added to break up the surface of an object and add visual interest, particularly in movie special effects.
noun: (psychology) Any of a set of invented novel objects used as stimuli in psychological studies of object and face recognition.
verb: (transitive) To add greebles to a surface.

(Definitions from Wiktionary)