In Greek mythology, Thoosa was a Nymph, one of Poseidon's lovers and mother of the Cyclops Polyphemus.
But Earthshaker Poseidon is a stubborn god,
constantly enraged about the Cyclops,
the one whose eye Odysseus destroyed,
godlike Polyphemus, the mightiest
of all the Cyclopes. Thoosa bore him,
a nymph, a daughter of that Phorcys
who commands the restless sea.
Odyssey Book 1
Dictionary of Greek Mythology