or on-line, on line

[on-lahyn, awn-]
See more synonyms for online on
  1. operating under the direct control of, or connected to, a main computer.
  2. connected by computer to one or more other computers or networks, as through a commercial electronic information service or the Internet.
  3. of or denoting a business that transmits electronic information over telecommunications lines: an online bookstore.
  4. available or operating on a computer or computer network: an online dictionary.
  5. by means of or using a computer: online shopping.
  6. Radio. (of a network) supplying affiliated stations with all or a substantial part of their programming.
  7. Television. of or relating to the final editing of a videotaped program.
  8. done or accomplished while in operation or active service: online maintenance.
  9. located on major routes or rail lines: online industries.
  1. with or through a computer, especially over a network.
Compare offline.

Origin of online

First recorded in 1945–50 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for online

wired, accessible, connected, linked, operative

Examples from the Web for online

Contemporary Examples of online

Historical Examples of online

British Dictionary definitions for online



  1. of, relating to, or concerned with a peripheral device that is directly connected to and controlled by the central processing unit of a computer
  2. of or relating to the internetonline shopping
  3. occurring as part of, or involving, a continuous sequence of operations, such as a production line
  1. while connected to a computer or the internet
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

Word Origin and History for online

in reference to computers, "directly connected to a peripheral device," 1950 (originally as on-line).

Online Etymology Dictionary, © 2010 Douglas Harper

online in Science


  1. Connected to or accessible by means of a computer or computer network.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

online in Culture


A term referring to locations on or use of the Internet. The term can be used to refer to a specific location or Web page (“Our sales catalogues can be found online at — ”) or to a personal activity (“I went online to find the information you wanted.”)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.