monohybrid cross vs crossing

monohybrid cross and crossing both are nouns.

Word	Noun	Adjective	Verb	Adverb
monohybrid cross	Yes	No	No	No
crossing	Yes	No	No	No

As nouns, crossing is a hypernym of monohybrid cross; that is, crossing is a word with a broader meaning than monohybrid cross:

monohybrid cross: hybridization using a single trait with two alleles (as in Mendel's experiments with garden peas)
crossing: (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids

Other hypernyms of monohybrid cross include cross, crossbreeding, hybridisation, hybridization, hybridizing, interbreeding.

monohybrid cross (noun)	crossing (noun)
hybridization using a single trait with two alleles (as in Mendel's experiments with garden peas)	a voyage across a body of water (usually across the Atlantic Ocean)
	traveling across
	(genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids
	a path (often marked) where something (as a street or railroad) can be crossed to get from one side to the other
	a junction where one street or road crosses another
	a point where two lines (paths or arcs etc.) intersect
	a shallow area in a stream that can be forded