- 1a stage in a process of change or development during the first/next/last phase the initial/final phase of the project a critical/decisive phase the design phase His anxiety about the work was just a passing phase. She's going through a difficult phase. The wedding marked the beginning of a new phase in Emma's life.
- 2each of the shapes of the moon as we see it from the earth at different times of the month the phases of the moon
- 1working/not working together in the right way The traffic lights were out of phase.
- 2(physics) if two or more light or sound wave cycles are in phase, their high and low points occur at the same time; if they are out of phase, they occur at different times
Check pronunciation: phase