A cur's taken on manoeuvres, bad-tempered (12)
I believe the answer is:
cantankerous
'bad-tempered' is the definition.
(thesaurus)
'a cur's taken on manoeuvres' is the wordplay.
'manoeuvres' is an anagram indicator (letters manoeuvred in a new way).
'a'+'curs'+'taken'+'on'='acurstakenon'
'acurstakenon' anagrammed gives 'CANTANKEROUS'.
(Other definitions for cantankerous that I've seen before include "Irritable" , "like a wrangler" , "Bloody-minded -- non-UK car seat (anag)" , "Contrary and quarrelsome" , "Awkward" .)