man-child vs child

man-child and child both are nouns.

Word	Noun	Adjective	Verb	Adverb
man-child	Yes	No	No	No
child	Yes	No	No	No

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

Other hypernyms of man-child include male, male person, kid.

man-child (noun)	child (noun)
a child who is male	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