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• phase-in
  phase-in

  noun

  an act or instance of phasing in; gradual introduction or implementation.
• phase in
  phase in

  verb

  (tr, adverb) to introduce in a gradual or cautious manner

phase-in

American  

[feyz-in] / ˈfeɪzˌɪn /

noun

1. an act or instance of phasing in; gradual introduction or implementation.

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phase in British  

verb

1. (tr, adverb) to introduce in a gradual or cautious manner

   the legislation will be phased in over two years

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phase in Idioms  

1. 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]

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Etymology

Origin of phase-in

Noun use of verb phrase phase in

Example Sentences

See Examples For:

phase-in phase in

More than a dozen other states have built robust, sustainable school-choice programs on the same foundation: clear rules, sensible phase-in, fund preapprovals, and resources dedicated to core academic expenses.

From The Wall Street Journal ● Jul. 12, 2026

That three-year phase-in is to apply only to those who need to retrofit their property, not to new construction.

From Los Angeles Times ● Feb. 2, 2025

FDA proposes a phase-in of the new rules over 4 years, but its specific demands aren’t yet clear.

From Science Magazine ● Dec. 12, 2023

Officials pushed back asking for a phase-in period, but the judge denied it.

From Seattle Times ● Oct. 6, 2023

Important commodities - such as sugar, rice and bananas - are virtually excluded by long phase-in periods.

From The Belgian Curtain Europe after Communism by Vaknin, Samuel

The WBG said the five-year CPF "marks a new phase in a 45-year partnership," as China moves from needing financing to primarily requiring technical assistance and knowledge sharing.

From Barron's ● Jul. 23, 2026

Volumes should be slightly down, as the 296 GTB phases out and the 849 Testarossa and Amalfi are only starting to phase in.

From The Wall Street Journal ● Jul. 7, 2026

"I know I have reached a certain phase in my career," Modric said recently.

From BBC ● Jul. 3, 2026

Another planned facility, Cosmic Explorer, is currently in the design phase in the United States.

From Science Daily ● Jul. 3, 2026

“I never planned to be a flight attendant forever. This is a new phase in my life.”

From "The Miseducation of Cameron Post" by emily m. danforth