online

American  

[on-lahyn, awn-] / ˈɒnˈlaɪn, ˈɔn- /

Or on-line,

adjective

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.

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adverb

1. with or through a computer, especially over a network.

online British  

/ ˈɒnˌlaɪn /

adjective

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 internet

   online shopping

3. occurring as part of, or involving, a continuous sequence of operations, such as a production line

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adverb

1. while connected to a computer or the internet

online Scientific  

/ ŏn′līn′ /

1. Connected to or accessible by means of a computer or computer network.

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online Cultural  

1. 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.”)

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Etymology

Origin of online

First recorded in 1915–20 (in sense “located on rail lines”); 1945–50 for other senses

Explanation

When you're online, you are using a computer or other device that's connected to the Internet. If someone asks if you're online, they're wondering whether you have Internet access. You might say, "I need to go online and check my email," or "I don't know if she's still meeting me — she hasn't been online all day." Or you could describe something that's available or readable on the Internet, like a news story, as being online. While the adjective officially describes a connection to any computer network, it's almost always used these days to mean "on the Internet." The word online has been around since 1950.

Example Sentences

The full connectome is now freely available online, giving researchers around the world a powerful new resource for neuroscience studies.

From Science Daily • Jun. 10, 2026

Platner said the online comments and his relations with Fifield came during a “very dark period” when he was struggling with his re-entry into civil society.

From The Wall Street Journal • Jun. 10, 2026

To apply for the deferment, homeowners need to fill out the “Misfortune and Calamity relief” form online from the Los Angeles County Assessor’s Office website.

From Los Angeles Times • Jun. 9, 2026

A Collins-aligned group is launching ads featuring Maine voters reading Platner's old online posts and calling him "too risky."

From Barron's • Jun. 9, 2026

I’m just going online when I see him begin drawing with Boo.

From "The Tenth Mistake of Hank Hooperman" by Gennifer Choldenko