Definition

1. Noun:

   • A distinct stage in a process of change or development: "Phase" refers to a specific period or step within a longer sequence of events or a gradual process.
   • (Astronomy) A particular appearance of the illuminated portion of a celestial body: Specifically, it describes the recurring shapes of the Moon (or a planet) as seen from Earth, based on its position relative to the Sun.
   • (Physical Chemistry) A distinct, homogeneous state of matter: In a system, a "phase" is a form of matter (e.g., solid, liquid, gas) that is uniform in chemical composition and physical properties, separated from other phases by a clear boundary.
   • A point or stage in a repeating cycle, often expressed as an angle: Used in technical contexts like wave mechanics to denote a specific position in a periodic cycle.

2. Verb:

   • To carry out or introduce something in stages: To plan and execute an activity in distinct, sequential steps.
   • To synchronize: To adjust the timing of one process so it coincides correctly with another.

Examples of Usage

• Noun:

  • The project is now entering its final phase. (The project is moving into its last distinct stage.)
  • We can see the first quarter phase of the Moon tonight. (We can see the Moon when half of its Earth-facing side is illuminated.)
  • Water can exist in the solid phase as ice. (Water can be in the distinct state of matter known as solid.)
  • The two sound waves are out of phase. (The two waves are at different points in their cycles, causing interference.)

• Verb:

  • The new policy will be phased over three years. (The new policy will be introduced in distinct stages across three years.)
  • The engineer phased the traffic lights to improve flow. (The engineer synchronized the timing of the traffic lights.)

Advanced Usage

• "to phase in": To introduce or implement something gradually.
  • The government will phase in the new tax regulations.
• "to phase out": To discontinue or remove something gradually.
  • The old software system is being phased out.
• "in phase/out of phase": (Technical) Describing whether two cyclic processes are synchronized or not.
  • The generators must operate in phase to avoid damage.

Variants and Related Words

• Phasic (adj): Relating to or having phases.
  • The treatment follows a phasic approach.
• Multiphase (adj): Involving several distinct phases.
  • It's a multiphase chemical reaction.

Synonyms

• Stage: A point, period, or step in a process.
• Period: A length or portion of time.
• State: A particular condition that something is in at a specific time.

Related Phrases (Phrasal Verbs)

• Phase in: (See "Advanced Usage" above).
• Phase out: (See "Advanced Usage" above).

Related Idioms

• A passing phase: A temporary stage or period, especially in someone's development or behavior.
  • Don't worry about his moodiness; it's just a passing phase.

Noun

1. (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
2. a particular point in the time of a cycle; measured from some arbitrary zero and expressed as an angle
3. (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
4. 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

Verb

1. adjust so as to be in a synchronized condition
   • he phased the intake with the output of the machine
2. arrange in phases or stages
   • phase a withdrawal