Pretty prompt about time (4)
I believe the answer is:
cute
'pretty' is the definition.
(I've seen this before)
'prompt about time' is the wordplay.
'prompt' becomes 'cue' (synonyms).
'about' indicates putting letters inside.
'time' becomes 't' (abbreviation).
'cue' placed around 't' is 'CUTE'.
(Other definitions for cute that I've seen before include "Astute - lovely" , "Shrewd" , "Taking" , "Precious" , "Endearing" .)