1 B2 neutral
To connect an external audio source to a device via the line input socket.
"Make sure you line in your guitar through the interface before recording."
separable
line in
B2 neutral transitive
A technical audio/electronics term referring to the input socket used to receive an external audio signal directly into a device.
In plain English
The socket you plug a music player or microphone cable into to send sound into a computer or speaker system.
What does "line in" mean?
One main meaning — here's how to use it.
Literal vs figurative
Words literally mean
A signal line coming in to a device — transparent in technical context.
Actually means
The socket you plug a music player or microphone cable into to send sound into a computer or speaker system.
Usage tip
Used as both a noun ('the line in socket') and occasionally as a verb phrase ('line in the signal'). Primarily a technical term in audio engineering and consumer electronics. Contrast with 'line out'. Not a traditional phrasal verb in the grammatical sense but included for learner reference.
Words that pair with "line in"
Natural word combinations native speakers use most often.
socket jack port cable signal audio microphone
How to conjugate "line in"
The five tense forms you'll use most often.
Base
line in
I/you/we/they
3rd person
lines in
he/she/it
Past simple
lined in
yesterday
Past participle
lined in
have + pp
-ing form
lining in
continuous
Hear "line in" in the wild
Listen to native speakers using "line in" in real YouTube videos — click a clip to watch it on Looplines.
Other ways to say "line in"
Swap in when you want variety — tap a linked one to explore it.
Keep exploring
Jump to every phrasal verb built on the same verb, particle, or level.