Steam Whistle
noun
A steam flute is a flute that goes off using steam. The only time I can think of this happening is via a steam whistle. Choo choooo!
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
まどの外から、汽車の汽笛が聞こえてきました。
We heard a steam train whistle coming from outside the window.
いいか？汽笛が鳴ったら、船から飛び下りるんだぞ。
You ready? You've gotta jump off the ship when the steam whistle blows.
昨日の夢で、幸運にもタイタニック号が汽笛を鳴らすところを見たよ。
In my dream last night, I was fortunate enough to witness the blowing of the Titanic’s steam whistles.