Was Menoetius a Titan?
Yes. Though he was not one of the original twelve Titans born to Gaia and Uranus, Menoetius was a son of one of those Titans (Iapetus) and thus a second-generation Titan himself.
Did Menoetius help the Titans in the Titanomachy?
Like his brother Atlas (but unlike his brothers Prometheus and Epimetheus), Menoetius sided with the Titans during the Titanomachy, the war fought between the Olympians and the Titans for control of the cosmos. When the Titans were defeated, he ended up in Tartarus along with the rest of the losing side.
The name “Menoetius” (Μενοίτιος, translit. Menoítios) appears to be related to the Greek words μένος (ménos), meaning “rage” or “might,” and οἶτος (oîtos), meaning “doom” or “fate.” Menoetius can thus be interpreted as “mighty doom.”
Menoetius Μενοίτιος (translit. Menoítios)
[muh-NEE-shee-uhs] /məˈni ʃi əs/
Hesiod, our main source for Menoetius’ mythology, describes the Titan as ὑπερκύδας (hyperkýdas), “renowned,” and ὑβριστής (hybristḗs), “insolent.” This second epithet in particular seems to encompass Menoetius’ personality.
As his epithets and even his name imply, Menoetius’ chief attribute was his insolence—what the Greeks called hybris (from which we derive the English word “hubris”). This insolence also characterized Menoetius’ more famous brother Prometheus, who repeatedly tried to outwit Zeus. This did not end well for either brother: Prometheus was finally chained to a rock, where an eagle tore out his liver each day, while Menoetius was struck down by Zeus’ lightning bolt “because of his mad presumption and exceeding pride.”
Menoetius was the son of the Titan Iapetus and his Oceanid wife, whose name was either Clymene or Asia. His siblings were Atlas, Prometheus, and Epimetheus, but also, according to some traditions, Anchiale, Buphagus, and Dryas.
Menoetius had a very limited mythology. The son of the Titan Iapetus and his wife (named either Clymene or Asia), Menoetius appears to have fought alongside the other Titans during the Titanomachy. This was the ten-year war between the Titans (led by Cronus) and the Olympians (led by Cronus’ son Zeus) for control of the cosmos.
In the end, the Titans lost the war and were cast into the darkness of Tartarus. The only Titans to escape this fate were those who had allied themselves with the Olympians—including Menoetius’ own brothers Prometheus and Epimetheus.
Menoetius himself, as the story goes, angered Zeus somehow, perhaps by fighting against him during the Titanomachy. For this act of “hubris,” Zeus struck him down with a lightning bolt before sending him to Tartarus with the rest of his Titan kin.