1. The appearance of the illuminated surface of a celestial body as seen from the Earth: Jill was very interested in astronomy and didn't want to miss out on any of the phases of the Moon.
2. One of the varying shapes of the lighted portion of the Moon: In her book, Susan read that there were many phases of the Moon, like the Full Moon, Half Moon, and the Waning Crescent, among others.

The period (as opposed to the "statary phase") in the activity cycle of an army ant colony during which the colony forages more actively for food and moves frequently from one bivouac site to another: Throughout the nomadic phase, the queen does not lay eggs, and the bulk of the brood is in the larval stage.

The period (as opposed to the "nomadic phase") in the activity cycle of an army ant colony during which the colony is relatively quiescent and does not move from site to site: At the time of the statary phase, the queen lays the eggs and the bulk of the brood is in the egg and in pupal states.