Friar unable to move, needing head released (4)
I believe the answer is:
tuck
'friar' is the definition.
(Friar Tuck)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for tuck that I've seen before include "Fold - grub" , "Schoolboy grub like sweets and cakes" , "Fold - friar!" , "legendary friar" , "Dart" .)