A distinguishable part of a sequence or cycle occurring over time.
That which is exhibited to the eye; the appearance which anything manifests, especially any one among different and varying appearances of the same object.
Any appearance or aspect of an object of mental apprehension or view.
astronomy: A particular appearance or state in a regularly recurring cycle of changes with respect to quantity of illumination or form, or the absence, of its enlightened disk; as, ''the phases of the moon or planets''. Illustrated in Wikipedia's article ''Lunar phase''.
physics: Any one point or portion in a recurring series of changes, as in the changes of motion of one of the particles constituting a wave or vibration; one portion of a series of such changes, in distinction from a contrasted portion, as the portion on one side of a position of equilibrium, in contrast with that on the opposite side.