noun a person who temporarily takes the place of another, especially in a sports team
verb to complete a form or document by providing requested information
preposition used to indicate that information should be added in a specific space or place
Students must fill in the blanks on the worksheet.
Applicants are required to fill in all sections of the job application.
Participants are asked to fill in their responses on the survey form.
Patients need to fill in their personal information on the medical intake form.
Users are prompted to fill in their username and password to log in.
Taxpayers must fill in their income and deductions on the tax return form.
In the context of a writer, 'fill in' may refer to completing missing information in a story, article, or script. It could also refer to temporarily taking over someone else's writing duties, such as filling in for a columnist or contributor.
For a psychologist, 'fill in' may involve completing missing details in a patient's history or behavior assessment. It could also refer to temporarily taking over therapy sessions or assessments for a colleague who is unavailable.