Phāse or PHĀ'-SES, n.
n.; pl. PHĀ'-SES. [Gr. φάσις, from φάειν, φαίνειν, to make to appear, passive to appear; Fr. phase, It. & Sp. fase.]
Sense 1. That which is exhibited to the eye; the appearance which any thing manifests, especially any one among different and varying appearances of the same object.
Sense 2. (Astron.) Appearance with respect to quantity of illumination or form of enlightened disk at any time in a cycle of changes, as of the moon or a planet.
Sense 3. (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 such changes in distinction from a contrasted portion, as on one side of a position equilibrium in distinction from the opposite side.
Sense 4. (Min.) Transparent green quartz.