illegitimate child vs whoreson

illegitimate child and whoreson both are nouns.

Word	Noun	Adjective	Verb	Adverb
illegitimate child	Yes	No	No	No
whoreson	Yes	No	No	No

As nouns, illegitimate child and whoreson are synonyms defined as:

illegitimate child and whoreson: the illegitimate offspring of unmarried parents

Other synonyms of illegitimate child include bastard, by-blow, illegitimate, love child.

illegitimate child (noun)	whoreson (noun)
the illegitimate offspring of unmarried parents	the illegitimate offspring of unmarried parents
	insulting terms of address for people who are stupid or irritating or ridiculous