crossing vs reciprocal

crossing and reciprocal both are nouns.

Word	Noun	Adjective	Verb	Adverb
crossing	Yes	No	No	No
reciprocal	Yes	Yes	No	No

As nouns, reciprocal is a hyponym of crossing; that is, reciprocal is a word with a more specific, narrower meaning than crossing:

crossing: (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids
reciprocal: hybridization involving a pair of crosses that reverse the sexes associated with each genotype

Other hyponyms of crossing include dihybrid cross, monohybrid cross, reciprocal cross, test-cross, testcross.

crossing (noun)	reciprocal (noun)
a voyage across a body of water (usually across the Atlantic Ocean)	hybridization involving a pair of crosses that reverse the sexes associated with each genotype
traveling across	(mathematics) one of a pair of numbers whose product is 1: the reciprocal of 2/3 is 3/2; the multiplicative inverse of 7 is 1/7
(genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids	something (a term or expression or concept) that has an inverse relation to something else
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

crossing (adjective)	reciprocal (adjective)
	concerning each of two or more persons or things; especially given or done in return
	of or relating to the multiplicative inverse of a quantity or function