Machine part with teeth (4)
I believe the answer is:
gear
'machine part with teeth' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for gear that I've seen before include "Equipment; car mechanism" , "Toothed wheel that interlocks with another" , "Toothed wheel mechanism" , "Equipment, clothing, goods" , "Clothes (first or second, perhaps?)" .)