Part of a necklace (4)
I believe the answer is:
bead
'part of a necklace' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bead that I've seen before include "Small ball with a hole through the middle" , "Small ornamental strung ball" , "Glass ball" , "Part of a necklace" , "A bit of the rosary" .)