bairn vs child

bairn and child both are nouns.

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

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

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

bairn (noun)	child (noun)
a child: son or daughter	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