Definition of "fill in" in English

Verb

1. To fill; to replace material that is absent or has been removed.

   • After you're done laying the pipe, fill in the trench.

2. To inform somebody, especially to supply someone missing or missed information.

   • If you know anything about this, maybe you can fill me in.

3. To substitute for somebody or something.

   • He can't go on vacation very often because there is nobody to fill in for him.

4. To complete a form or questionnaire with requested information.

   • I've got a form that is to be filled in in ink.

5. To beat up; to physically assault.

   • Talk to me like that again and I'll fill you in!