phase

phase — noun

1. one part of a longer process, plan, or period of change.

1.nounB2
Definition

one part of a longer process, plan, or period of change.

Example

The project entered its final phase after six months of testing.

pattern: final phase of a project

In the first phase, workers repaired the old bridge deck.

pattern: in the first phase

Common collocations
  • early phase
  • final phase
  • phase of the project
  • move into a new phase
  • next phase of work
Synonyms
  • stage

    the closest synonym, often used for a clearly named part of a process

  • step

    usually focuses on one action rather than a whole period

  • period

    broader and less tied to development or change

  • chapter

    often figurative for a part of life or history

Grammar Patterns

enter a phase

in the early/final phase

phase of + process/project

Usage Note

Often used with words like early, next, and final, and with verbs such as enter and move into. Distinguish from sense 2, which is about a temporary period of odd or difficult behaviour.

Common Mistakes

We are in the final phrase of the project.
We are in the final phase of the project.
phase means a stage; phrase means a group of words.

2. a limited period when someone behaves in an unusual or difficult way, especially

2.nounB2
Definition

a limited period when someone behaves in an unusual or difficult way, especially while growing up.

Example

Ben went through a loud phase and banged every kitchen pot.

pattern: go through a phase

During her angry phase, Maya refused to speak at dinner.

Common collocations
  • go through a phase
  • shy phase
  • angry phase
  • biting phase
  • have a phase
Synonyms
  • stage

    possible in some contexts, but less typical for temporary behaviour

  • spell

    often suggests a fairly short period

  • period

    broader and does not especially suggest changing behaviour

  • patch

    informal and often used for a difficult time

Grammar Patterns

go through a phase

be in a + adjective/noun + phase

have a phase

Usage Note

Usually appears with go through, be in, or have, and the words before phase often name the behaviour, such as angry, shy, or biting. Distinguish from sense 1, which describes a stage in a process rather than someone's temporary manner.

Common Mistakes

My son passed a biting phase.
My son went through a biting phase.
English normally uses 'go through' with this sense.

3. one of the different shapes the moon seems to have during its monthly cycle.

3.nounB2
Definition

one of the different shapes the moon seems to have during its monthly cycle.

Example

Tonight's phase of the moon looks like a thin silver bowl.

pattern: phase of the moon

The children drew each moon phase on black paper circles.

compound: moon phase

Common collocations
  • phase of the moon
  • moon phase
  • full-moon phase
  • crescent phase
Synonyms
  • appearance

    broader and not limited to the moon's regular cycle

  • shape

    states the visual form, but not the repeating cycle

  • stage

    can describe a point in the moon's cycle, though it is less standard

Grammar Patterns

phase of the moon

moon phase

full-moon phase

Usage Note

Most often used in the set phrases phase of the moon, moon phase, and full-moon phase. This sense is much narrower than sense 1 and refers specifically to the moon's changing appearance.

Idioms

in phase/out of phase (with something)

idiom

Two or more things are working together correctly or not working together correctly.

The two machines are in phase and run smoothly together.

Why are the speakers out of phase with each other?

phase — verb

Synonym discussion

Sense: noun/1

For noun/1, phase is useful when you divide a longer process into clear parts. Stage is the closest everyday synonym, but it can sound more fixed or official, as in stage 2 of a plan. Step usually focuses on one action in a sequence, not a whole period of development. Period is broader and may simply mean a length of time, so it is less precise. Chapter is often figurative and is common for parts of life or history. Use phase when change or progress matters: 'The bridge repair entered a new phase.' Use step for one action: 'First, mix the flour and water.'

stage ↗step ↗period ↗chapter ↗

Etymology

GreekLatinFrenchEnglish

Phase came into English through French and Latin from Greek phasis, meaning 'appearance'. It first referred to the visible appearance of the moon, and from that idea English later developed the broader sense of a stage in a process or period of change.