Origin of log

1350–1400; Middle English logge, variant of lugge pole, limb of tree; compare obsolete logget pole; see lugsail, logbook

Related forms

log·gish, adjectiveun·logged, adjective

Definition for log in (2 of 2)


[ noun lawg-in, log-; verb lawg-in, log- ]
/ noun ˈlɔgˌɪn, ˈlɒg-; verb ˌlɔgˈɪn, ˌlɒg- /
Digital Technology

noun Also log-in, logon.

the act of logging in to a database, mobile device, or computer, especially a multiuser computer or a remote or networked computer system.
a username and password that allows a person to log in to a computer system, network, mobile device, or user account.

verb (used without object)

to log in: Login with your new password. See log1(def 17).

Usage note

Many who are neither professionals in the computer field nor amateur tech enthusiasts condemn the use of the solid form login as a verb, and with reason. It doesn’t behave like a normal verb. You cannot say you have loginned, and you are never in the process of loginning. Moreover, you cannot even ask someone to login you; you must ask that person to log you in. Clearly, it is the two-word phrase log in that functions fully as an English verb and not the solid form. Normally, we would expect log in, the verb phrase and login, the noun to behave in the same way as similar pairs: blow out/blowout, crack down/crackdown, hang up/hangup, splash down/splashdown, turn off/turnoff, where the two-word phrase is a verb and the one-word form a noun.
And yet, this gluing together of terms like login, logon, backup, and setup as verbs is common, especially in writing about computers. Not for everyone, however. Some well-known software companies, for example, carefully maintain the distinction in their programs and documentation.
But habits are difficult to change. Those who react to the one-word verb as an error will probably have to get used to it, and those who use the one-word verb will have to recognize that others will see it and wince.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for log in (1 of 3)

log in

/ computing /


Also: log on to enter (an identification number, password, etc) from a remote terminal to gain access to a multiaccess system


Also: login the process by which a computer user logs in

British Dictionary definitions for log in (2 of 3)


/ (lɒɡ) /


verb logs, logging or logged

Word Origin for log

C14: origin obscure

British Dictionary definitions for log in (3 of 3)


/ (lɒɡ) /


short for logarithm
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for log in


[ lôg ]

A logarithm.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with log in (1 of 2)

log in

Also, log on. Enter into a computer the information needed to begin a session, as in I logged in at two o'clock, or There's no record of your logging on today. These expressions refer especially to large systems shared by numerous individuals, who need to enter a username or password before executing a program. The antonyms are log off and log out, meaning “to end a computer session.” All these expressions derive from the use of log in the nautical sense of entering information about a ship in a journal called a log book. [c. 1960]

Idioms and Phrases with log in (2 of 2)


In addition to the idiom beginning with log

  • log in

also see:

  • easy as pie (rolling off a log)
  • like a bump on a log
  • sleep like a log
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.