Definition of phase in English:

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Pronunciation: /fāz/


1A distinct period or stage in a process of change or forming part of something’s development: the final phases of the war [as modifier]: phase two of the development is in progress
More example sentences
  • The country hopes to pass the next key threshold of 25 chapters and reach the final phase of the negotiation process, he said after the meeting.
  • The final phase of the planning process is orders production, which centers on developing the CHS casualty treatment and evacuation plan.
  • Although agriculture is still caught in the grips of industrialization, corporatization is the final phase of the industrial process.
stage, period, chapter, episode, part, step, point, time, juncture
1.1A stage in a person’s psychological development, especially a period of temporary unhappiness or difficulty during adolescence or a particular stage during childhood: you are not obsessed, but you are going through a phase
More example sentences
  • Perhaps Jason is right that it is just children going through a phase which will soon stop but somehow I doubt it; it has been going on for years.
  • Separation and individuation are normal and healthy phases of infancy.
  • On the other hand, there remains the issue of identification with the father, which brought to a close the Oedipal phase.
period, stage, time, spell, patch
1.2Each of the aspects of the moon or a planet, according to the amount of its illumination, especially the new moon, the first quarter, the full moon, and the last quarter.
Example sentences
  • The second condition is that the Sun, Earth and the Moon must also be lined up, corresponding to the phase of the New Moon.
  • A star chart is simply a printed diagram of the sky on a given night or month, with prominent constellations, planets and phases of the moon marked.
  • He discovered moons orbiting Jupiter, phases of Venus, sunspots, and features on the Moon that made it seem more like a planet.
aspect, shape, form, appearance, state, condition
1.3 Riding Each of the separate events in an eventing competition.
Example sentences
  • The morning started off with the final phase of the eventing competition, the show jumping.
  • As these are newer bits, the USEA was interested to learn more about them when considering approving them for use in the dressage phase of eventing.
  • Davidson was the clear winner of the dressage phase, finishing with a score of 47.21.
2 Zoology A genetic or seasonal variety of an animal’s coloration.
2.1A stage in the life cycle or annual cycle of an animal.
Example sentences
  • Floods cue fish to spawn, for instance, and trigger certain insects to begin a new phase in their life cycles.
  • Volvox carteri, like all related green flagellates, is haploid in all active phases of the life cycle, which greatly facilitates isolation of mutants.
  • Spined soldier bug adults are strong fliers and, during responsive phases of their life cycle, will fly toward the pheromone from considerable distances.
3 Chemistry A distinct and homogeneous form of matter (i.e., a particular solid, liquid, or gas) separated by its surface from other forms.
Example sentences
  • Intermolecular interactions are most significant in liquid and solid phases where molecules are very close together.
  • Similarly, molecules in the gas phase occasionally strike the surface and are captured by the attraction of molecules in the liquid or solid phase.
  • Such a disappearance of a solid into the gas phase was an intriguing phenomenon.
4 Physics The relationship in time between the successive states or cycles of an oscillating or repeating system (such as an alternating electric current or a light or sound wave) and either a fixed reference point or the states or cycles of another system with which it may or may not be in synchrony.
Example sentences
  • Because we desire to store digital information, our system should have differing phases corresponding to the differing values of the information.
  • The interaction strength and the relative phase of the electric field in neighboring particles both depend on polarization and frequency.
  • Both phy and cry photoreceptors are presumably involved in setting the phase under white light: dark cycles.


[with object]
1Carry out (something) in gradual stages: the work is being phased over a number of years (as adjective phased) a phased withdrawal of troops
More example sentences
  • He believes phasing the withdrawal has its benefits.
  • The development at Newhall Park Road became fully operational in October last year after a three-week move phasing departments from the old site next door to the new building.
  • Councillors suggested possible solutions of phasing the scheme; considering other schemes; and seeking funding from partners.
1.1 (phase something in/out) Introduce into (or withdraw from) use in gradual stages: our armed forces policy was to be phased in over 10 years
More example sentences
  • She however, said the introduction of unleaded fuel would be gradual as it would be phased in slowly beginning this month.
  • He added that any introduction of defibrillators would be phased in, but the aim was for there to be one machine on every engine.
  • The company says changes will be phased in gradually, with half the project completed by the end of this year and fully realised by 2005.
introduce gradually, begin to use, ease in
withdraw gradually, discontinue, stop using, run down, wind down
2 Physics Adjust the phase of (something), especially so as to synchronize it with something else.
Example sentences
  • In order to properly phase the two telescopes, adaptive optics on both telescopes removed the distortion caused by the Earth's atmosphere.


See faze (usage)


in (or out of) phase

Being or happening in (or out of) synchrony or harmony: the cabling work should be carried out in phase with the building work
More example sentences
  • Large species tend to produce their young more in phase with high biomass and after the protein peak.
  • Advisory committees help colleges and universities stay in phase with industry needs.
  • When exiting the corner, the rear wheels turn in phase with the front wheels improving yaw damping.


Early 19th century (denoting each aspect of the moon): from French phase, based on Greek phasis 'appearance', from the base of phainein 'to show'.

  • A phase first described an aspect of the moon, but had developed the modern sense of a distinct period by 1701. It is from French phase, based on Greek phasis ‘appearance’.

Words that rhyme with phase

ablaze, amaze, appraise, baize, Blaise, blaze, braise, broderie anglaise, chaise, craze, daze, écossaise, erase, faze, gaze, glaze, graze, Hayes, Hays, haze, laze, liaise, lyonnaise, maize, malaise, Marseillaise, mayonnaise, Mays, maze, phrase, polonaise, praise, prase, raise, raze, upraise

For editors and proofreaders

Syllabification: phase

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