Synonyms for Call off:

n.

compromise, buckle, arbitrate, concede, bridge-building, conciliate, break up, concession. forget, back out, back down, forgo, think better of something, pull back, knock something on the head, hold back. get off someone's case, give someone a break, let up, leave/let someone alone, let someone be, back off, call off the/your dogs. call off (noun)
call, cancel.
cancel (noun)
stop, discontinue, postpone, halt.

v.

discontinue (verb)
cancel, postpone.
motion (verb)
call.
social (verb)
cancel.

Other synonyms:

conciliate, forget, back down, forgo, bridge-building, arbitrate, back out. hold back, break up. pull back, stop. concede, concession. Other relevant words:
postpone, discontinue, stop.