waif vs child

waif and child both are nouns.

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

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

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

waif (noun)	child (noun)
a homeless child especially one forsaken or orphaned	a young person of either sex
	a human offspring (son or daughter) of any age
	an immature childish person
	a member of a clan or tribe