rāhú m. (fr. √ rabh; cf. graha and √ grah) ‘the Seizer’, N. of a Daitya or demon who is supposed to seize the sun and moon and thus cause eclipses (he is fabled as a son of Vipra-citti and Siṃhikā and as having a dragon's tail; when the gods had churned the ocean for the Amṛta or nectar of immortality, he disguised himself like one of them and drank a portion; but the Sun and Moon revealed the fraud to Viṣṇu, who cut off Rāhu's head, which thereupon became fixed in the stellar sphere, and having become immortal through drinking the Amṛta, has ever since wreaked its vengeance on the Sun and Moon by occasionally swallowing them; while at the same time the tail of the demon became Ketu [q.v.] and gave birth to a numerous progeny of comets and fiery meteors; in astron. Rāhu is variously regarded as a dragon's head, as the ascending node of the moon [or point where the moon intersects the ecliptic in passing northwards], as one of the planets [cf. graha], and as the regent of the south-west quarter [[Laghuj.]] ; among Buddhists many demons are called Rāhu), [AV.] &c. &c.
an eclipse or (rather) the moment of the beginning of an occultation or obscuration, [VarBṛS.]