log in verb2 •To gain access to a computer system, usually by providing a previously registered username and password.I would like to log in to check my e-mail, but I can't remember my password. •To be placed at a certain ranking.Their cover version of Bobby "Blue" Bland's "Turn On Your Love Light" logged in at number 80 in 1968. — 1990 formslogged in · logging in · logs in