Lies if coming up with abuse regularly (4)
I believe the answer is:
fibs
'lies' is the definition.
(fib is a kind of lie)
'if coming up with abuse regularly' is the wordplay.
'coming up' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'abuse' are 'bs'.
'if' in reverse letter order is 'fi'.
'fi'+'bs'='FIBS'
(Other definitions for fibs that I've seen before include "Trivial lies as by child" , "Little white lies" , "Harmless little lies" .)