siren vs sexual activity

siren and sexual activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
siren	Yes	No	No	No
sexual activity	Yes	No	No	No

siren (noun)	sexual activity (noun)
eellike aquatic North American salamander with small forelimbs and no hind limbs; have permanent external gills	activities associated with sexual intercourse
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