phase

One part of a process or period of development.

• The project has three phases.
• We are entering the final phase of training.
• Their daughter is going through a difficult phase.

How to use it: phase of something (The first phase of construction is complete.)

Similar words: stage, period

Common phrases: first phase, final phase, phase of development, early phase

The position in a repeating movement or change that shows whether things happen together.

• The waves are in phase.
• The two signals are out of phase.
• A small phase difference changes the combined sound.

How to use it: in phase with something (The two signals are in phase with each other.); out of phase with something (One wave is out of phase with the other.)

Common phrases: in phase, out of phase, phase difference

One side of a subject or problem that can be considered separately.

• We discussed another phase of the problem.
• He studied every phase of the subject.
• The social phase of the issue received little attention.

How to use it: phase of something (Her book examines every phase of the question.)

Similar words: aspect, side, facet

Common phrases: another phase, every phase, phase of something

To introduce or stop using something gradually over a period of time.

• We plan to phase out plastic bags.
• The factory phased in safer equipment.
• These older models are being phased out this year.

How to use it: phase something in (The company will phase in the new software.); phase something out (The city plans to phase out diesel buses.)

Common phrases: phase something in, phase something out, phase out something

To introduce something gradually, a little at a time.

• We will phase in the changes.
• The school phased in its new rules last year.
• They are phasing the equipment in one department at a time.

How to use it: phase something in (We will phase the new system in over six months.)

Similar words: introduce gradually

Common phrases: phase in something, phase something in