Tokei (時計) means 'watch,' 'clock,' or 'timepiece.' It's any device that tells time, whether it's worn on the wrist as a watch or displayed on a wall as a clock. For example, if your time-telling device stops, you can say, '私の時計は止まっています' (My watch/clock has stopped).

時間がわかる「時計」のことです。腕につけるものも、壁にかけるものも。例：時計を見ます。