pull in one's horns vs pull back

pull in one's horns and pull back both are verbs.

Word	Noun	Adjective	Verb	Adverb
pull in one's horns	No	No	Yes	No
pull back	No	No	Yes	No

As verbs, pull in one's horns and pull back are synonyms defined as:

pull in one's horns and pull back: make a retreat from an earlier commitment or activity

Other synonyms of pull in one's horns include back away, back out, crawfish, crawfish out, retreat, withdraw.

pull in one's horns (verb)	pull back (verb)
make a retreat from an earlier commitment or activity	make a retreat from an earlier commitment or activity
	move to a rearward position; pull towards the back
	stretch back a bowstring (on an archer's bow)
	use a surgical instrument to hold open (the edges of a wound or an organ)
	pull back or move away or backward