acoustic

US /əˈkuː.stɪk/
UK /əˈkuː.stɪk/
"acoustic" picture
1.

relating to sound or the sense of hearing

:
The concert hall has excellent acoustic properties.
We need to improve the acoustic insulation in this room.
2.

of a musical instrument, not having electrical amplification

:
He prefers playing an acoustic guitar.
The band performed an acoustic set at the cafe.
1.

an acoustic musical instrument

:
He brought his acoustic to the jam session.
The band decided to play a few acoustics for the intimate crowd.