1. self-insert - Noun
2. self-insert - Verb
(fandom slang) A character in a story who represents the author's own person.
(fandom slang) A character in a story who the reader/viewer is meant to identify with.
To insert oneself.
To insert something into one's own body.
(fandom slang) To insert one's own person into a story as a character.
Source: en.wiktionary.org