To sign again; to provide one's signature again.
To sign a contract renewing or restarting a professional relationship, such as that of a professional athlete with a sports team.
To sign; to put one's name to.
To support, lend support to, guarantee the basis of.
To agree to pay by signing one's name; subscribe.
Specifically, to assume financial responsibility for something, and guarantee it against failure.
To act as an underwriter.
To write below or under; subscribe.