Instant suspicion after time with wife (9)
I believe the answer is:
twinkling
'instant' is the definition.
('twinkling' can be a synonym of 'instant')
'suspicion after time with wife' is the wordplay.
'suspicion' becomes 'inkling' (I've seen this before**).
'after' says to put letters next to each other.
'time' becomes 't'.
'with' means one lot of letters go next to another.
'wife' becomes 'w'.
't'+'w'='tw'
'inkling' put after 'tw' is 'TWINKLING'.
(Other definitions for twinkling that I've seen before include "Sparkling - moment" , "Bat of an eye" , "Shining intermittently" , "Sparkling like a star" , "How stars appear" .)