Wiktionary
n. A hollow-body guitar of the older variety, in contradistinction to an electric guitar.
WordNet
n. sound is not amplified by electrical means
Wikipedia
An acoustic guitar is a guitar that produces sound acoustically—by transmitting the vibration of the strings to the air—as opposed to relying on electronic amplification (see electric guitar). The sound waves from the strings of an acoustic guitar resonate through the guitar's body, creating sound. This typically involves the use of a sound board and a sound box to strengthen the vibrations of the strings.
The main source of sound in an acoustic guitar is the string, which is plucked or strummed with the finger or with a plectrum. The string vibrates at a necessary frequency and also create many harmonics at various different frequencies. The frequencies produced can depend on string length, mass, and tension. The string causes the soundboard and sound box to vibrate, and as these have their own resonances at certain frequencies, they amplify some string harmonics more strongly than others, hence affecting the timbre produced by the instrument.
Acoustic Guitar is a monthly magazine published in the United States since July/August 1990 by String Letter Publishing. The magazine offers information, inspiration, and instruction related to acoustic guitars for players of all levels from beginners to teachers. Each issue includes three or so songs with notation and tablature, lessons, product reviews and interviews of prominent acoustic musicians. The magazine boasts a readership of approximately 54,000 and a social media audience that numbers more than 490,000 likes on Facebook, and is widely available throughout North America.
Acoustic Guitar was Preston Reed's first release on Sky Records. It subsequently went out-of-print.
Usage examples of "acoustic guitar".
Blonde too, quite small, semi-acoustic guitar, dressed very similarly to the bloke.
The bald, bomber-jacketed goon I saw at the apartment hops the rail and hands her an acoustic guitar.
When she came out in her kimono he was sitting on the bed wrapped around her acoustic guitar, playing scales with a quick, light touch.
As Winnie waited for a table, she heard the strum of a twangy acoustic guitar.
The sandy-haired teacher looked up, as did an equally sandy-haired girl with an acoustic guitar on her lap.
All it will be, after all, is half a dozen songs played on an acoustic guitar in front of half a dozen people.
Closer by, someone was playing an acoustic guitar, fingerpicking it.
If acoustic guitar ever came back, I'd be masochistically tempted to turn the bar over to Tom and go back on the road.
He played an acoustic guitar in an electronic agecertainly it sounded mellower than contemporary instruments, but mostly it was older.
Paul strummed upon an acoustic guitar, but it was after three in the morning and he was strumming the blues (in A minor), so that was permissible.
I heard music as I lay in sleep, astonishingly lovely music, a woman singing, accompanied by an acoustic guitar.
Toussaint picked at his acoustic guitar, playing a complicated version of 'When the Levee Breaks.
At the moment they were rendering Don Ross's percussive acoustic guitar, an excellent choice for a sunset.
But all the singing was being done by his accompanist: a tall skinny galoot with long brown hair and a beard, playing an acoustic guitar.