phase

[ feyz ]

noun

1. any of the major appearances or aspects in which a thing of varying modes or conditions manifests itself to the eye or mind.

   Synonyms: side, facet, shape, form

2. a stage in a process of change or development:

   Each phase of life brings its own joys.

3. a side, aspect, or point of view:

   This is only one phase of the question.

4. a state of synchronous operation:

   to put two mechanisms in phase.

5. Astronomy.
   1. the particular appearance presented by the moon or a planet at a given time.
   2. one of the recurring appearances or states of the moon or a planet in respect to the form, or the absence, of its illuminated disk:

      the phases of the moon.

6. Zoology. color phase.
7. Chemistry. a mechanically separate, homogeneous part of a heterogeneous system:

   the solid, liquid, and gaseous phases of a system.

8. Physics. a particular stage or point of advancement in a cycle; the fractional part of the period through which the time has advanced, measured from some arbitrary origin often expressed as an angle phase angle, the entire period being taken as 360°.

verb (used with object)

, phased, phas·ing.

1. to schedule or order in gradual stages, so as to be available when or as needed.
2. Physics. to adjust the phase of (an electrical or mechanical device), especially to synchronize it with that of one or more other devices:

   a properly phased, synchronous pulse generator that augments the action of the human heart.

verb phrase

1. to put or come into use gradually; incorporate by degrees:

   to phase in new machinery.

2. to reduce by gradual stages.
3. to bring or come to an end gradually; ease out of service:

   to phase out obsolescent machinery.

phase

/ feɪz /

noun

1. any distinct or characteristic period or stage in a sequence of events or chain of development

   there were two phases to the resolution

   his immaturity was a passing phase

2. astronomy one of the recurring shapes of the portion of the moon or an inferior planet illuminated by the sun

   the new moon, first quarter, full moon, and last quarter are the four principal phases of the moon

3. physics
   1. the fraction of a cycle of a periodic quantity that has been completed at a specific reference time, expressed as an angle
   2. ( as modifier )

      a phase shift

4. physics a particular stage in a periodic process or phenomenon
5. in phase
   (of two waveforms) reaching corresponding phases at the same time
6. out of phase
   (of two waveforms) not in phase
7. chem a distinct state of matter characterized by homogeneous composition and properties and the possession of a clearly defined boundary
8. zoology a variation in the normal form of an animal, esp a colour variation, brought about by seasonal or geographical change
9. biology usually in combination a stage in mitosis or meiosis

   prophase

   metaphase

10. electrical engineering one of the circuits in a system in which there are two or more alternating voltages displaced by equal amounts in phase (sense 5) See also polyphase
11. (in systemic grammar) the type of correspondence that exists between the predicators in a clause that has two or more predicators; for example connection by to, as in I managed to do it, or -ing, as in we heard him singing

verb

1. often passive to execute, arrange, or introduce gradually or in stages

   a phased withdrawal

2. sometimes foll by with to cause (a part, process, etc) to function or coincide with (another part, process, etc)

   he phased the intake with the output

   he tried to phase the intake and output of the machine

3. to arrange (processes, goods, etc) to be supplied or executed when required

phase

/ fāz /

1. Any of the forms, recurring in cycles, in which the Moon or a planet appears in the sky.
2. One of a set of possible homogenous, discrete states of a physical system. States of matter such as solid and liquid are examples of phases, as are different crystal lattice structures in metals such as iron.
3. See also phase transition
4. A measure of how far some cyclic behavior, such as wave motion, has proceeded through its cycle, measured in degrees or radians. At the beginning of the phase, its value is zero; at one quarter of its cycle, its phase is 90 degrees (π/2 radians); halfway through the cycle its value is 180 degrees (π radians), and so on.
5. ◆ The phase angle between two waves is a measure of their difference in phase. Two waves of the same frequency that are perfectly in phase have phase angle zero; if one wave is ahead of the other by a quarter cycle, its phase angle 90 degrees (π/2 radians); waves that are perfectly out of phase have phase angle 180 degrees (π radians), and so on.
6. See more at wave

Derived Forms

• ˈphaseless, adjective
• ˈphasic, adjective

Other Words From

• phase·less adjective
• pha·sic pha·se·al [feyz, -, uh, l], adjective
• re·phase verb (used with object) rephased rephasing
• sub·phase noun
• un·phased adjective

Word History and Origins

Origin of phase¹

First recorded in 1805–15; (noun) back formation from phases, plural of phasis

Word History and Origins

Origin of phase¹

C19: from New Latin phases, pl of phasis, from Greek: aspect; related to Greek phainein to show

Example Sentences

Vaccinating hundreds of thousands of people before phase 3 trials conclude means those people could be harmed by any of these potential side effects.

From Vox

Of the hundreds of potential Covid-19 vaccines in development, six are in the final stages of testing, known as phase three clinical trials.

From Singularity Hub 

“We will keep working with the team from UCSD as we make decisions about when to move into subsequent phases of reopening,” he said.

From Voice of San Diego

According to reports, an unconfirmed number of job losses are planned as part of its next phase of cost-saving.

From Digiday

In other words, my fueling needs and ability to recover from workouts may change depending on whether I’m in a low-hormone phase or a high-hormone phase.

From Outside Online

The next phase of the trial consists of vaccinating Ebola workers on the front lines.

From The Daily Beast

The families announced along with it that they had entered a “phase of silence” surrounding the details of the new deal.

From The Daily Beast

To that end, the budget postpones federal phase-out of incandescent electric bulbs.

From The Daily Beast

Instead, the military commission proceedings are bogged down in a pre-trial phase, as it has been for the past three years.

From The Daily Beast

Arriving in Italy means they have made it to the next phase, but they have most certainly not reached the end of their journeys.

From The Daily Beast

But between the phase of schooling and the phase of adult learning there is an intermediate stage.

From Project Gutenberg

The moment he passed out of her sight some phase of individuality promptly lit its torch.

From Project Gutenberg

But this was but a passing phase, and soon the thirst for glory called the young soldier to sterner things.

From Project Gutenberg

The second phase was the dangerous one for Rita, and during a certain luncheon at Romanos her fate hung in the balance.

From Project Gutenberg

These short studies reflect every phase of Voltaire's sparkling genius.

From Project Gutenberg

Related Words

• aspect
• chapter
• development
• point
• stage
• state
• step
• time