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90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.



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adjective formal costly pronunciation in American English /ˈkɔs(t)li/ 
Word Forms
  1. 1
    costing a lot of money

    They have been investing in costly new equipment.

    a costly business/process/exercise:

    Changing your company's management style can be a costly business.

    1. a.
      used about something that costs more money than you want to pay

      Appeals can be costly and time-consuming.

  2. 2
    causing a lot of problems

    Dropping the ball with only seconds left to play was a costly mistake.


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