phase

/feɪz/
verb
  1. To introduce or carry out something gradually in stages.
    • They will phase out older models by the end of the year.
    • The government is phasing in stricter emissions standards.
    • The company plans to phase in the new software over several months.
noun
  1. A distinct stage or period in a process of change or development.
    • The first phase of the construction will take six months.
    • The project is currently in the planning phase.
    • Teenagers often go through a rebellious phase.
  2. Each of the apparent shapes of the moon or a planet as seen from Earth, determined by its position relative to the sun.
    • We observed the crescent phase of Venus through the telescope.
    • The moon goes through eight phases during its cycle.
    • During the full moon phase, the night sky is very bright.
  3. A stage in a periodic process, such as a wave or oscillation, measured as an angle.
    • In alternating current, voltage and current can be in or out of phase.
    • Engineers adjusted the phase of the signal to improve reception.
    • The two sound waves are out of phase, causing interference.