Hustlers, crooked and without pity (8)
I believe the answer is:
'without pity' is the definition.
('pity' can be 'ruth' (as opposed to ruthlessness) so maybe 'without pity' can be ''ruthless')
'hustlers crooked' is the wordplay.
'crooked' indicates anagramming the letters (a crooked or disrupted version of the letters).
'hustlers' is an anagram of 'RUTHLESS'.
'and' is the link.
(Other definitions for ruthless that I've seen before include "devoid of compassion" , "Having no mercy like hustlers" , "Without pity, merciless" , "Brutal" , "nasty" .)