Object to nurse cutting break (6)
I believe the answer is:
resent
'object to' is the definition.
(I've seen this before)
'nurse cutting break' is the wordplay.
'nurse' becomes 'en' (abbreviation for enrolled nurse).
'cutting' means one lot of letters goes inside another (some letters cut their way into a word).
'break' becomes 'rest' (rest is a kind of break**).
'en' going within 'rest' is 'RESENT'.
(Other definitions for resent that I've seen before include "Take something as an affront" , "Object to" , "Feel bad about" , "Feel bitterness at (something)" , "Hold bitter memory, begrudge" .)