yearling vs child

yearling and child both are nouns.

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

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

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

yearling (noun)	child (noun)
an animal in its second year	a young person of either sex
a racehorse considered one year old until the second Jan. 1 following its birth	a human offspring (son or daughter) of any age
a young child who is just beginning to walk	an immature childish person
	a member of a clan or tribe