My dad whistled tunelessly through his teeth.

我爸爸从牙缝里乱吹口哨，曲不成调。

《柯林斯英汉双解大词典》

He had an irritating habit of singing tunelessly about the house.

他有个恼人的习惯，老在屋子里不成调地唱歌。

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Thomas squatted on the forward deck, whistling tunelessly, polishing the broze spool of the anchor winch.

托马斯蹲在前甲板上擦起锚绞车的黄铜轴，边擦边胡乱吹着口哨。

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Dessay shook his hand warmly, encouraged him to experiment with the acoustics of the house by delivering a few whoops, and prodded him to sing a few bars of Mozart, which he did enthusiastically and tunelessly.

NEWYORKER: Man Behind the Curtain