Small ball with a hole through the middle (4)
I believe the answer is:
bead
'small ball with a hole through the middle' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for bead that I've seen before include "bit off necklace, say" , "Part of a necklace" , "A bit of the rosary" , "Drop of liquid on a surface" , "Necklace element" .)