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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

The 50% U.S. content proposal is likely to be viewed skeptically by many automakers, who would struggle to source half of their content from U.S. sources, particularly if there is only a short phase-in period.

From The Wall Street Journal ● May 29, 2026

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

But that was before the legislation was narrowed down to include a years-long phase-in plan.

From Los Angeles Times ● Oct. 13, 2023

The board decided to skip the phase-in process and defer immediately to the national governing bodies for each sport.

From Washington Times ● Oct. 5, 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

His opener in the dramatic, extraordinary 3-2 victory in Miami was his 20th World Cup finals goal - extending the record he broke during his country's progression through the group phase in the United States.

From BBC ● Jul. 4, 2026

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

From Science Daily ● Jul. 3, 2026

The commissioners plan to develop a five-year plan to phase in state funding, along with enforceable standards like caseload limits and access to defense investigators.

From Los Angeles Times ● Jun. 21, 2026

“It’s taken time, I swear. I went through this whole emo phase in middle school where I played with the alias ‘Rick.’”

From "When Dimple Met Rishi" by Sandhya Menon