adapter

American  

[uh-dap-ter] / əˈdæp tər /

Or adaptor

noun

1. a person or thing that adapts.

2. 1. a connector for joining parts or devices having different sizes, designs, etc., enabling them to be fitted or to work together.

   2. Also called adapter plug.  Also called plug adapter,.  a device that connects an electrical plug to an outlet that has a different plug shape.

      Last time I traveled, I brought the wrong adapter.

   3. Also called power adapter.  Also called AC adapter,.  a device with a cord that plugs into an electrical outlet and functions as an external power supply for a small or portable electronic device, usually converting AC current to DC.

      I forgot to plug in the adapter, and my laptop died.

3. an accessory to convert a machine, tool, or part to a new or modified use.

4. Computers.

   1. expansion card.

   2. an external device containing the necessary circuitry to connect to or work with another device or system.

      a network adapter;

      a wireless adapter;

      a video adapter.

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Other Word Forms

• nonadapter noun
• nonadaptor noun

Etymology

Origin of adapter

First recorded in 1795–1805; adapt + -er ¹

Explanation

When you have two pieces of equipment that can't be connected directly, you may need an adapter to plug one into another. You might need an adapter to connect your cellphone to a computer. Computers, televisions, and cameras are just some of the devices that often require adapters to be charged or used in different ways. One common kind of adapter makes it possible to put a two-pronged plug into an outlet with three holes. A different way to use the word adapter is for a person who changes — or adapts — one work of art to fit in a different medium, like an adapter who writes an opera based on a comic book.

Example Sentences

"We call it the universal adapter," Schultheiß explains.

From Science Daily • Mar. 27, 2026

He said he ran into the shop, where he saw an adapter charging system - full of chargers - under the counter and a small fire.

From BBC • Mar. 10, 2026

To charge it at home, I used my Level 2 charger with an adapter, since China uses different plugs.

From The Wall Street Journal • Jan. 30, 2026

The most practical option was an old-school corded phone and a cellular-to-landline adapter.

From Slate • Jan. 27, 2026

A small refrigerator is plugged into an adapter that has six different electrical devices all feeding into one outlet.

From "Counting by 7s" by Holly Goldberg Sloan

Related Words

• connection