phase

To experience or be in the midst of a temporary period of change, development, or fluctuation. I went through a phase of being obsessed with superhero movies this summer. Timothy has been really aggressive and demanding lately, but I think he's just going through a phase.

The short amount of time at the beginning of a new relationship, activity, or pursuit when everything goes well and seems to be free of problems. Donna was excited when she started her new job, but once the honeymoon phase was over, she realized that she had more responsibilities than she could handle. Many couples find it difficult to maintain a relationship after the honeymoon phase ends.

to work someone or something into use or service gradually. They decided to phase Ruth into the job little by little. They phased in Ruth over a long period of time.

to work someone or something out of use or service or out of a group gradually. We are going to have to phase you out of the job of treasurer. They phased out the unneeded workers.

to introduce something gradually in stages The plan would phase in a pay raise for many state-government workers. They added too many stores at once instead of phasing them in over time.

to gradually stop providing or using something The city decided to phase out half-day kindergarten for 4-year-olds in the public schools.

Also, in sync. In a correlated or synchronized way; in accord, in harmony. For example, If everyone were in phase we could step up the schedule, or John and Pat often say the same thing at the same time; their minds are perfectly in sync . Both versions of this idiom refer to physical phenomena. The first, dating from the second half of the 1800s, alludes to being at the same stage in a series of movements. The second, a slangy abbreviation of synchronization dating from the mid-1900s, alludes to exact coincidence in the time or rate of movement. Also see in step; phase in; for the antonym, see out of phase.

Also, out of sync. In an unsynchronized or uncorrelated way. For example, Inventory control and shipping are out of phase, so we can't rely on their figures, or The lights are out of sync and keep flashing at random. For dates, see the antonym in phase.

Introduce one stage at a time. For example, New technology must be phased in or the office will be overwhelmed. The antonym is phase out, meaning "to bring or come to an end, one stage at a time," as in The department is phasing out all the older computers. [Mid-1900s]

In a correlated or synchronized way.

In an unsynchronized or uncorrelated way.