phase

nouns

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"

phase, stage

(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"

form, phase

a particular point in the time of a cycle; measured from some arbitrary zero and expressed as an angle

phase, phase angle

(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"

phase

domain category

the branch of physics that studies celestial bodies and the universe as a whole

astronomy, uranology

is a type of (narrower)

outward or visible aspect of a person or thing

appearance, visual aspect