Condescend to stop holding one's head (5)
I believe the answer is:
stoop
'condescend' is the definition.
(I've seen this before)
'stop holding one's head' is the wordplay.
'holding' is an insertion indicator.
'head' says to take the initial letters.
The first letter of 'ones' is 'o'.
'stop' placed around 'o' is 'STOOP'.
'to' acts as a link.
(Other definitions for stoop that I've seen before include "Stand bent forward" , "Lower one's standards" , "Bow or bend" , "dive" , "Sink" .)