siren vs adult female

siren and adult female both are nouns.

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

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

Other hypernyms of siren include woman.

siren (noun)	adult female (noun)
eellike aquatic North American salamander with small forelimbs and no hind limbs; have permanent external gills	an adult female person (as opposed to a man)
an acoustic device producing a loud often wailing sound as a signal or warning
a warning signal that is a loud wailing sound
a woman who is considered to be dangerously seductive