Flirt like everybody in extremes of depravity (5)
I believe the answer is:
dally
'flirt' is the definition.
(synonyms)
'everybody in extremes of depravity' is the wordplay.
'everybody' becomes 'all' (all people).
'in' indicates putting letters inside.
'extremes of' means to remove the middle letters (only the letters at the extremes of the word).
'depravity' with its centre taken out is 'dy'.
'all' inserted within 'dy' is 'DALLY'.
'like' is the link.
(Other definitions for dally that I've seen before include "Linger" , "Procrastinate" , "Trifle" , "Dawdle - delay" , "Move slowly" .)