Short for motorcycle; a motorbike — an engine-powered two-wheeled vehicle.
週末は友達とバイクでツーリングに行く予定だ。
I'm planning to go touring on a bike with friends this weekend.
新しいバイクを買って、免許を取ったばかりだ。
I bought a new motorcycle and just got my license.
ヘルメットはバイクに乗るとき必ず着用してください。
Be sure to wear a helmet when riding a motorcycle.
Sometimes used to mean bicycle, especially in compounds or certain contexts (e.g., mountain bike).
マウンテンバイクで山道を下るのは楽しい。
Riding a mountain bike down mountain trails is fun.
ピストバイクは街乗りでも人気だ。
Fixed-gear bikes are also popular for riding around town.
子どものバイク（自転車）に補助輪を付けた。
I put training wheels on my child's bike (bicycle).