• 笛ふえ — flute / whistle
• 警笛けいてき — alarm whistle, horn
• 汽笛きてき — steam whistle
• 口笛くちぶえ — whistle (with mouth)
• 号笛ごうてき — signal whistle
• 吹笛すいてき — blowing flute

The kanji 笛 combines the bamboo radical 竹 with the phonetic element 由 (ユ・テキ) to express a flute or whistle made from bamboo. These instruments have been used in Japan since ancient times for music, rituals, and signaling.