Lite-Brite piece (3)
I believe the answer is:
peg
'lite-brite piece' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for peg that I've seen before include "Wooden or plastic pin for hanging clothes" , "that may have hat or coat on" , "Small cylindrical pin" , "The woman" , "Member" .)