Twinge about inclination (5)
I believe the answer is:
cramp
'twinge' is the definition.
(thesaurus)
'about inclination' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'inclination' becomes 'ramp' (an inclined surface).
'c'+'ramp'='CRAMP'
(Other definitions for cramp that I've seen before include "Muscular spasm, very painful" , "Severe muscular pain" , "Involuntary and painful contraction of a muscle" , "Confine - muscular spasm" , "Involuntary muscular contraction" .)