Have obligation to take on credit for shrink (5)
I believe the answer is:
cower
'for shrink' is the definition.
(shrink can mean to cower from something)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for cower that I've seen before include "Shrink back in fear" , "Show abject fear" , "Cringe, crouch" , "Cringe in fear" , "to emulate Burns's wee beastie" .)