willing vs selection

willing and selection both are nouns.

Word	Noun	Adjective	Verb	Adverb
willing	Yes	Yes	No	No
selection	Yes	No	No	No

As nouns, selection is a hypernym of willing; that is, selection is a word with a broader meaning than willing:

Other hypernyms of willing include choice, option, pick.

willing (noun)	selection (noun)
the act of making a choice	the act of choosing or selecting
	the person or thing chosen or selected
	a passage selected from a larger work
	an assortment of things from which a choice can be made
	a natural process resulting in the evolution of organisms best adapted to the environment

willing (adjective)	selection (adjective)
disposed or inclined toward
not brought about by coercion or force