Part of a crossword that gets filled in Crossword Clue

 The answer to the crossword clue "part of a crossword that gets filled in" is ENTRY.

An entry is a word or phrase that is filled in a crossword puzzle. Entries are typically listed in a clue, which gives the solver a hint as to what the entry is.

Entries can be of any length, but they are typically at least three letters long. They can be common words, obscure words, or even phrases.

The entries in a crossword puzzle are arranged in a grid, and they must fit together so that all of the squares in the grid are filled in.

Solving a crossword puzzle can be a fun and challenging way to improve your vocabulary and your problem-solving skills.