plug-in

1 of 3

adjective

ˈpləg-ˌin 

: designed to be connected to an electric circuit by plugging in

a plug-in toy

a plug-in circuit board

plug-in

2 of 3

noun

1

: something that plugs in

2

: a small piece of software that supplements a larger program (such as a browser)

plug in

3 of 3

verb

plugged in; plugging in; plugs in

intransitive verb

: to establish an electric circuit by inserting a plug

transitive verb

: to attach or connect to an electric receptacle (such as an outlet)

Examples of plug-in in a Sentence

Recent Examples on the Web

Adjective

According to the California Energy Commission, more than 99,000 zero-emission vehicles were sold in Los Angeles County in 2024 alone, including battery electric, plug-in hybrid and fuel cell electric vehicles. —Danielle Wallace, Fox News, 30 Jan. 2025

Those policies call for 100% of new vehicles to be zero-emission (including plug-in hybrids) by 2035, and have been adopted by other states. —Camila Domonoske, NPR, 30 Jan. 2025

Noun

Enlarge Ars Technica AutoPacific broke the data out into those looking for internal combustion engine vehicles, plug-in hybrid electric vehicles, or battery EVs. —Jonathan M. Gitlin, Ars Technica, 24 Mar. 2023

Witricity has previously conducted a couple pilots with BMW on the 5 series plug-in hybrid in Europe and California using its WPT. —Sam Abuelsamid, Forbes, 23 Mar. 2023

Word History

First Known Use

Adjective

1922, in the meaning defined above

Noun

1946, in the meaning defined at sense 1

Verb

1903, in the meaning defined at intransitive sense

Kids Definition

plug-in

1 of 2 noun

ˈpləg-ˌin

: software that adds to the capabilities of a larger program (as a browser)

plug in

2 of 2 verb

: to establish an electric circuit by inserting a plug