|Origin:||phasis, from Greek, 'appearance of a star, phase of the moon', from phanein 'to show, appear'|
phase1 W2 [countable]
one of the stages of a process of development or change:
a new drug that is in the experimental phase
The first phase of renovations should be finished by January.
The work will be carried out in phases.
It's just a phase he's going through.
2 British English
not happening together in the right way:
Nizan's views were out of phase with the political climate of the time.
3 British English
happening together in the right way:
The electrical work will be carried out in phase with the other renovations.
one of a fixed number of changes in the appearance of the moon or a planet when it is seen from the Earth