crawfish vs back out

crawfish is a noun but back out is not a noun.

Word	Noun	Adjective	Verb	Adverb
crawfish	Yes	No	Yes	No
back out	No	No	Yes	No

As verbs, crawfish and back out are synonyms defined as:

crawfish and back out: make a retreat from an earlier commitment or activity

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

crawfish (noun)	back out (noun)
large edible marine crustacean having a spiny carapace but lacking the large pincers of true lobsters
small freshwater decapod crustacean that resembles a lobster
tiny lobster-like crustaceans usually boiled briefly

crawfish (verb)	back out (verb)
make a retreat from an earlier commitment or activity	make a retreat from an earlier commitment or activity
	move out of a space backwards