¹phase

noun \ˈfāz\

: a part or step in a process : one part in a series of related events or actions

: a short period of time during which a person behaves in a particular way or likes a particular thing

: the shape of the part of the moon that is visible at different times during a month

Full Definition of PHASE

: a particular appearance or state in a regularly recurring cycle of changes <phases of the moon>

a : a distinguishable part in a course, development, or cycle <the early phases of her career>

b : an aspect or part (as of a problem) under consideration

: the point or stage in a period of uniform circular motion, harmonic motion, or the periodic changes of any magnitude varying according to a simple harmonic law to which the rotation, oscillation, or variation has advanced from its standard position or assumed instant of starting

: a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physicochemical system

: an individual or subgroup distinguishably different in appearance or behavior from the norm of the group to which it belongs; also : the distinguishing peculiarity

— pha·sic \ˈfā-zik\ adjective

— in phase

: in a synchronized or correlated manner

— out of phase

: in an unsynchronized manner : not in correlation

See phase defined for English-language learners

See phase defined for kids

Origin of PHASE

New Latin phasis, from Greek, appearance of a star, phase of the moon, from phainein to show (middle voice, to appear) — more at fancy

First Known Use: circa 1750

Related to PHASE

Synonyms: angle, facet, hand, aspect, side

²phase

verb

phasedphas·ing

Definition of PHASE

transitive verb

: to adjust so as to be in a synchronized condition

: to conduct or carry out by planned phases

: to introduce in stages —usually used with in <phase in new models>

See phase defined for English-language learners

First Known Use of PHASE

1904

PHASING Defined for Kids

phase

noun \ˈfāz\

Definition of PHASE for Kids

: a step or part in a series of events or actions : stage <I have completed the first phase of my training.>

: the way that the moon or a planet looks to the eye at any time in its series of changes with respect to how it shines <The new moon and the full moon are two phases of the moon.>

Medical Dictionary

phase

noun \ˈfāz\

Medical Definition of PHASE

: a particular appearance or state in a regularly recurring cycle of changes

: a distinguishable part in a course, development, or cycle <the early phases of a disease>

: a point or stage in the period of a periodic motion or process (as a light wave or a vibration) in relation to an arbitrary reference or starting point in the period

: a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physicochemical system; especially : one of the fundamental states of matter usually considered to include the solid, liquid, and gaseous forms

: an individual or subgroup distinguishably different in appearance or behavior from the norm of the group to which it belongs; also : the distinguishing peculiarity