Feeling that gets one's back up? (5)
I believe the answer is:
hunch
'feeling' is the definition.
(I know that hunch is a type of feeling)
'one's back up?' is the wordplay.
I cannot really see how this works, but
'one' could be 'un' (northern English dialect form of 'one') and 'un' is located in the answer.
This explanation may well be incorrect...
'that gets' acts as a link.
Can you help me to learn more?
(Other definitions for hunch that I've seen before include "Bend over" , "Premonition; hump" , "Vague suspicion" , "Idea based on intuition" , "Intuitive guess" .)