(transitive) To write at full length or in expanded form.
(transitive) To write or fill out (a ticket or citation).
(broadly, transitive) To exclude from a narrative or history.
(broadly, transitive) To remove (a character in a fictional series such as a TV show) by writing the script so as to explain their disappearance (through death, moving away, etc.).
(intransitive) To exhaust one's mental capacity by too much writing.