Scotchwoman vs adult female

Scotchwoman and adult female both are nouns.

Word	Noun	Adjective	Verb	Adverb
Scotchwoman	Yes	No	No	No
adult female	Yes	No	No	No

As nouns, adult female is a hypernym of Scotchwoman; that is, adult female is a word with a broader meaning than Scotchwoman:

Other hypernyms of Scotchwoman include Scot, woman.

Scotchwoman (noun)	adult female (noun)
a woman who is a Scot	an adult female person (as opposed to a man)