sign out

Short definition from Wiktionary

Verb

1. 1
   To sign one's name as an indication that one is leaving some location; to take some action to indicate one is leaving a secured program or web page on a computer.
2. 2
   To remove (something) and take (it) into one's possession, having registered or signed for it in some way as a record of possession and a promise to return it (e.g., by your signature or log-in credentials).
3. 3
   To signal.
4. 4
   To say something through sign language.

Noun

1. 1
   An instance of signing out; a procedure executed when exiting a facility, ending a computer session, etc.