Bending over, possibly demonstrating hiding head (7)
I believe the answer is:
arching
'bending over' is the definition.
'arching' can be an answer for 'bending' (arching is a kind of bending). I'm not certain of the 'over' bit.
'demonstrating hiding head' is the wordplay.
'demonstrating' becomes 'marching' ('march' can be a synonym of 'demonstrate').
'hiding head' means to remove the first letter.
'marching' with its first letter removed is 'ARCHING'.
'possibly' is the link.
Can you help me to learn more?
(Another definition for arching that I've seen is " Bending".)