Menacing senior nurse holding hip? (8)
I believe the answer is:
sinister
'menacing' is the definition.
('sinister' can be a synonym of 'menacing')
'senior nurse holding hip?' is the wordplay.
'senior nurse' becomes 'sister' (I've seen this before).
'holding' indicates putting letters inside.
'hip?' becomes 'in' (I've seen this in other clues).
'sister' going around 'in' is 'SINISTER'.
(Other definitions for sinister that I've seen before include "What is left on bearings" , "Threatening; evil-looking" , "Suggestive of evil, being lefthanded" , "Threatening - ominous" , "Very unpleasant" .)