Short for 'synthesizer', a synth is an electronic keyboard that can make many different sounds.
Synths are often used in popular music and can make people think of the 1980s or futuristic music.
Examples:
I play the synth in my band.
The synth can make cool sounds.
The synth is on the stage.
The synth is my favorite instrument.
In the future, everyone will play a synth.
I want to learn to play the synth.