1. (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;
- "the reaction occurs in the liquid phase of the system"
- synonym： form
2. any distinct time period in a sequence of events;
- "we are in a transitional stage in which many former ideas must be revised or rejected"
- synonym： stage
3. a particular point in the time of a cycle; measured from some arbitrary zero and expressed as an angle
- synonym： phase angle
4. (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);
- "the full phase of the moon"
1. arrange in phases or stages;
- "phase a withdrawal"
2. adjust so as to be in a synchronized condition;
- "he phased the intake with the output of the machine"