The Cyclops were represented as one-eyed giants in Greek mythology. Their name is also spelled Cyclopes.
According to the Greek epic poet Hesiod, the Cyclops were the sons of Uranus (Sky) and Gaia (Earth). Hesiod names the Cyclops Argos, Steropes, and Brontes. The Titans and Hecatonchires (or Hundred-handers), both known for their size, may have been other offspring of Uranus and Gaia. Even though Uranus was their father, he lacked paternal instincts. Instead, he had the nasty habit of keeping all his children imprisoned -- inside their mother, Gaia.
When the Titan Cronus decided to help his mother by overthrowing his father, Uranus, the Cyclops helped. But Cronus was no better than Uranus. Instead of rewarding them for their assistance, Cronus imprisoned them in Tartarus.
Zeus who, in turn, overthrew his own father (Cronus), set the Cyclops free. Since they were metal workers and blacksmiths, they repaid Zeus with the a thank you gift of thunder and lightning. The Cyclops also gifted the gods Poseidon with a trident and Hades with the Helmet of Darkness.
Their time in fortune's favor was limited, though.
Apollo slew the Cyclops after they struck his son Asclepius with lightning.
Besides Hesiod, the other major Greek epic poet and transmitter of Greek mythology was the story teller we call Homer. Homer's Cyclops are different from Hesiod's, starting with their origin, since they are the sons of Poseidon. They share with Hesiod's Cyclops immensity, strength, and the single eye. The giant Polyphemus, whom Odysseus encounters in his ten-year return sea voyage from Troy, is a cyclops.
plural: cyclopes, kyklopes, kuklopes.