write-in

Short definition from Wiktionary

Noun

1. 1
   A candidate whose name is not listed on the ballot.
2. 2
   A vote made for a candidate of this kind.
3. 3
   A social event for authors, at which they meet up to work on their writing together.
4. 4
   A clue or puzzle that is so easy that the answer is immediately obvious.

Verb

1. 1
   To write a letter to, e.g. a publication.
2. 2
   To fill in something required, by writing.
3. 3
   To vote for a candidate not on the ballot by writing his or her name.