SPROCKET
cog, sprocket
(noun) tooth on the rim of gear wheel
sprocket, sprocket wheel
(noun) thin wheel with teeth that engage with a chain
sprocket
(noun) roller that has teeth on the rims to pull film or paper through
Source: WordNet® 3.1
Etymology
Noun
sprocket (plural sprockets)
(mechanical engineering) A toothed wheel that enmeshes with a chain or other perforated band.
(usually, in the plural) The tooth of such a wheel.
(architecture) A flared extension at the base of a sloped roof.
A placeholder name for an unnamed, unspecified, or hypothetical manufactured good or product.
Synonym: widget
Usage notes
Although sprockets are sometimes referred to as gears, there is a technical distinction between the two: sprockets interact with chains, whereas gears interact with other gears.
Anagrams
• pet rocks
Source: Wiktionary