cross-fertilize vs fertilise

cross-fertilize and fertilise both are verbs.

Word	Noun	Adjective	Verb	Adverb
cross-fertilize	No	No	Yes	No
fertilise	No	No	Yes	No

As verbs, fertilise is a hypernym of cross-fertilize; that is, fertilise is a word with a broader meaning than cross-fertilize:

Other hypernyms of cross-fertilize include fecundate, fertilize, inseminate.

cross-fertilize (verb)	fertilise (verb)
cause to undergo cross-fertilization	introduce semen into (a female)
undergo cross-fertilization; become fertile	provide with fertilizers or add nutrients to
	make fertile or productive