I.a turn, turning:
1.τροπαὶ ἠελίοιο the tropics or solstices, i. e. midsummer and midwinter, Lat. solstitium and bruma, when the sun appears to turn his course and cross the ecliptic. Hom. speaks of τροπαὶ ἠελίοιο as denoting a point in the heavens, prob. to the westward, Od.; τροπαὶ θεριναί and χειμεριναί, Hdt., attic:—when τροπαί is used alone, it mostly refers to the winter solstice, περὶ ἡλίου τροπάς (sc. χειμερινάς) Thuc.
2.a turn, change, = μεταβολή, Aeschin., Plut.