kid vs infant

kid and infant both are nouns.

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

As nouns, infant is a hyponym of kid; that is, infant is a word with a more specific, narrower meaning than kid:

kid: a human offspring (son or daughter) of any age
infant: a very young child (birth to 1 year) who has not yet begun to walk or talk

Other hyponyms of kid include army brat, babe, baby, female offspring, male offspring, man-child, stepchild.

kid (noun)	infant (noun)
young goat	a very young child (birth to 1 year) who has not yet begun to walk or talk
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

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