log on

from WordNet (r) 3.0 (2006)

log on
    v 1: enter a computer; "Have you logged in lately?" [syn: {log
         in}, {log on}, {log-in}] [ant: {log off}, {log out}]

from The Collaborative International Dictionary of English v.0.48

log in \log in\, log on \log on\, v. i. (Computers)
   To establish communication with a host computer from a
   terminal or remote computer.
   [PJC] Logistic