one-off
US
UK one-off n: mainly UK, informal ([sth] done once only) (非正式用语)
SC 一次性事件 yí cì xìng shì jiàn
SC 昙花一现 yí cì xìng shì jiàn，tán huā yí xiàn
The song was a one-off and the group never produced another hit.
那首歌只是昙花一现，其乐队再也没能推出其他的热门歌曲。
one-off adj: mainly UK, informal (happening only once)
SC 一次性的 yí cì xìng de
I had a one-off chance to hear Sixto Rodriguez sing.
let one off, let one go v expr: UK, slang, figurative (pass intestinal gas)
SC 放屁 fàng pì
SC 排气 fàng pì，pái qì
TC 排氣
TC 排氣
Did you just let one off?