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fill in - definition and synonyms

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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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phrasal verb
Word Forms
present tense
I/you/we/theyfill in
he/she/itfills in
present participlefilling in
past tensefilled in
past participlefilled in
  1. 1
    [transitive] to add information such as your name or address in the empty spaces on an official document

    Please fill in your name and address in the space provided.

    I spent over two hours filling in the application form.

    Fill in the missing words.

    fill in the blanks (=to give or learn information that is needed in order to understand something properly):

    We know roughly how the system works, but Brian is here to fill in the blanks.

  2. 2
    [transitive] same as fill

    The canal is now disused and partly filled in.

  3. 3
    [transitive] fill someone in informal to give someone details about something

    Did Sam fill you in about the new project?

    My secretary will fill you in on the details.

  4. 4
    [intransitive] to do someone’s job for them while they are away
    fill in for:

    I’m filling in for the receptionist at the moment.

See also main entry: fill

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