Flower part in ring? About time (5)
I believe the answer is:
petal
'flower part' is the definition.
(I know this)
'ring? about time' is the wordplay.
'ring?' becomes 'peal' ('peal' can be a synonym of 'ring').
'about' is an insertion indicator.
'time' becomes 't' (abbreviation).
'peal' placed around 't' is 'PETAL'.
'in' is the link.
(Other definitions for petal that I've seen before include "A bit of flower" , "Flower part seen on plate" , "A bit of a bloomer" , "Small seal set in a ring" , "part taken from stock?" .)