silly vs child

silly and child both are nouns.

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

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

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

silly (noun)	child (noun)
a word used for misbehaving children	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

silly (adjective)	child (adjective)
dazed from or as if from repeated blows
ludicrous, foolish
lacking seriousness; given to frivolity
inspiring scornful pity