To substitute for somebody or something.
To complete a form or questionnaire with requested information.
To beat up; to physically assault.
To fill; to replace material that is absent or has been removed.
To inform somebody, especially to supply someone missing or missed information.
To substitute for; to replace; (theater) to serve as an understudy.
To make one of a party in a bet or other speculation.
To take a side in a dispute.
A substitute; a replacement.