(astronomy) the particular appearance of a body's state of illumination (especially one of the recurring shapes of the part of Earth's moon that is illuminated by the sun) | apoapsis in Earth orbit; the point in its orbit where a satellite is at the greatest distance from the Earth |
(physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary | a final climactic stage |
any distinct time period in a sequence of events | |
a particular point in the time of a cycle; measured from some arbitrary zero and expressed as an angle | |