Reportedly yield an ovule (4)
I believe the answer is:
seed
'an ovule' is the definition.
(I know that seed is a type of ovule)
'reportedly yield' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'yield' becomes 'cede' (synonyms).
'cede' sounds like 'SEED'.
(Other definitions for seed that I've seen before include "From which things grow" , "Race" , "something in the garden" , "- Pearl; - capital" , "Top Wimbledon player" .)