Synonyms for Kick back:

n.

repay, return, rest, recharge your batteries, while away, lounge around, refund, idle away, pay, sit back, wind down. kick back (noun)
kick, recoil.

v.

contact (verb)
kick, recoil.
relax (verb)
sit back, rest, wind down.

Other synonyms:

Other relevant words:
repay, pay, sit back, refund, rest, wind down.