interbreed vs crossbreed

interbreed is not a noun while crossbreed is a noun.

Word	Noun	Adjective	Verb	Adverb
interbreed	No	No	Yes	No
crossbreed	Yes	No	Yes	No

As verbs, interbreed and crossbreed are synonyms defined as:

interbreed and crossbreed: breed animals or plants using parents of different races and varieties

Other synonyms of interbreed include cross, hybridise, hybridize.

interbreed (noun)	crossbreed (noun)
	(genetics) an organism that is the offspring of genetically dissimilar parents or stock; especially offspring produced by breeding plants or animals of different varieties or breeds or species

interbreed (verb)	crossbreed (verb)
breed animals or plants using parents of different races and varieties	breed animals or plants using parents of different races and varieties