Stitch in time gives clue (4)
I believe the answer is:
hint
'clue' is the definition.
(synonyms)
'stitch in time gives' is the wordplay.
'gives' indicates the answer is hidden within the clue.
'HINT' can be found hidden inside 'stitch in time'.
(Other definitions for hint that I've seen before include "Intimate" , "Tip-off" , "CRT screen coating" , "Indicate indirectly" , "Imply, suggest" .)