sign on

verb
High School
1

To join something, after signing.

2

To commit oneself, as to a project, a goal, an organization, a cause.

3

To begin broadcasting a radio or television signal, usually at the beginning of a broadcasting day and after being off the air for several hours.

4

To log on; to start using a computer, radio, or other multicast device; to start talking.

5

To apply to receive unemployment benefits.