1.
tone-deaf; unable to sing in tune
A person who cannot distinguish or reproduce musical pitch accurately. Composed of 音 (sound, tone) + 痴 (foolish, lacking sense). The original and most common meaning.
2.
having no sense of ~; being hopeless at ~
Used with a prefix to indicate a lack of ability or awareness in a particular area. A productive suffix pattern in modern Japanese, applied to directions, machines, fashion, and other domains.
Usage
The suffix pattern ~音痴 is very productive in casual Japanese. Common combinations include:
- 方向音痴 (no sense of direction — the most common extended use)
- 機械音痴 (hopeless with machines/technology)
- 運動音痴 (unathletic, having no coordination)
- 味音痴 (having no sense of taste)
Note that while 音痴 can be used about oneself self-deprecatingly, calling someone else 音痴 directly can be rude.