eat in

/IY1 T IH0 N/
verb
  1. 1

    To eat a meal at home.

  2. 2

    To eat a purchased meal on the premises where one bought it, rather than taking it away.

  3. 3

    (of acid) To etch or erode a substance.

Source: https://en.wiktionary.org/wiki/eat%20in