waif vs kid

waif and kid both are nouns.

Word	Noun	Adjective	Verb	Adverb
waif	Yes	No	No	No
kid	Yes	No	Yes	No

As nouns, kid is a hypernym of waif; that is, kid is a word with a broader meaning than waif:

Other hypernyms of waif include child, fry, minor, nestling, nipper, shaver, small fry, tiddler, tike, tyke, youngster.

waif (noun)	kid (noun)
a homeless child especially one forsaken or orphaned	young goat
	a young person of either sex
	a human offspring (son or daughter) of any age
	soft smooth leather from the hide of a young goat

waif (verb)	kid (verb)
	be silly or tease one another
	tell false information to for fun