Wiktionary
first quarter
n. (context astronomy English) The waxing lunar phase, from new moon to half way between new moon and full moon.
WordNet
first quarter
n. the first fourth of the moon's period of revolution around the Earth
Usage examples of "first quarter".
For the first quarter of the seventeenth century, all the cards seemed to be stacked against the Iroquois.
The moon was in its first quarter, and by its light we could dimly see, far ahead, the outline of the island of Tofoa.
The moon was entering her first quarter, and her insufficient light would soon die out in the mist on the horizon.