What does 口笛 mean?
口笛 is a Japanese noun meaning “whistle (sound made with the lips)” in English. It is written as 口笛 in kanji, くちぶえ in hiragana, and kuchibue in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
彼はメロディーを口笛で吹き始めた。
He began to whistle a tune.