Why is the ninth month called September?
c.1300, from Old French geant, earlier jaiant (12c.), from Vulgar Latin *gagantem (nominative gagas), from Latin gigas "giant," from Greek gigas (genitive gigantos), one of a race of savage beings, sons of Gaia and Uranus, eventually destroyed by the gods, probably from a pre-Greek language. Replaced Old English ent, eoten, also gigant. The Greek word was used in Septuagint to refer to men of great size and strength, hence the expanded use in modern languages. Of very tall persons from 1550s; of persons who have any quality in extraordinary degree, from 1530s.
In þat tyme wer here non hauntes Of no men bot of geauntes. [Wace's Chronicle, c.1330]
in folklore, huge mythical being, usually humanlike in form. The term derives (through Latin) from the Giants (Gigantes) of Greek mythology, who were monstrous, savage creatures often depicted with men's bodies terminating in serpentine legs. According to the Greek poet Hesiod, they were sons of Ge ("Earth") and Uranus ("Heaven"). The Gigantomachy was a desperate struggle between the Giants and the Olympians. The gods finally prevailed through the aid of Heracles the archer, and the Giants were slain. Many of them were believed to lie buried under mountains and to indicate their presence by volcanic fires and earthquakes. The Gigantomachy became a popular artistic theme (found, for example, on the frieze adorning the great altar at Pergamum), and it was interpreted as a symbol of the triumph of Hellenism over barbarism, of good over evil.