Lovers' tiff (4)
I believe the answer is:
spat
'lovers' tiff' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for spat that I've seen before include "Petty quarrel - gaiter" , "Petty row" , "Showed contempt" , "Minor difference" , "Unimportant quarrel between Pats" .)