whiff

n.

1. 些微的气味、空气或烟
   • A whiff of fresh air cleared his head.
     他吸了一点新鲜空气后头脑清醒了。
2. (呼吸时)吸入的少量的某物
   • He lost consciousness at the first whiff of ether.
     他一嗅到乙醚便失去了知觉。
3. 〈口〉难闻的气味
   • Now and again, he caught a whiff of a peculiar smell.
     他不时闻到一股怪味。