Cryptic clue about Republican devoid of pity (5)
I believe the answer is:
cruel
'devoid of pity' is the definition.
(I've seen this before)
'cryptic clue about republican' is the wordplay.
'cryptic' is an anagram indicator (a cryptic or obscure order of the letters).
'about' is an insertion indicator.
'republican' becomes 'R' (political abbreviation).
'clue' with letters rearranged gives 'cuel'.
'cuel' enclosing 'r' is 'CRUEL'.
(Other definitions for cruel that I've seen before include "Brutal" , "Very unkind" , "Callous" , "Ulcer (anag)" , "Merciless" .)