sign up

Verb

sign up (third-person singular simple present signs up, present participle signing up, simple past and past participle signed up)

1. (transitive) To add a name to the list of people who are participating in something.
   • We signed Bob up for kitchen cleanup duty.

   Synonyms:

   register, enroll

2. (intransitive) To add one's own name to the list of people who are participating in something (including amateur, but not professional, teams).
   • Coordinate term: sign in
   • Terry signed up for the soccer team.

   Synonyms:

   register, reserve, book, schedule, enroll

   Antonyms:

   cancel, resign

3. (intransitive) To agree to purchase some good or service.
   • After much deliberation we decided to sign up for satellite TV.
4. (intransitive) To enlist in the armed forces.
   • Didn't you hear? He's just signed up!

   Synonyms:

   enlist