1 [I] to breathe air in through the nose in a way that makes a sound, especially because you have a cold or you are crying 哧哧地用鼻吸气（尤指因患伤风或哭泣）: Stop sniffing and blow your nose. 不要再呼哧呼哧的，擤一下鼻子吧。

2 [I,T] sniff (at) sth to smell sth by sniffing 嗅；闻 [T] ‘I can smell gas,’ he said, sniffing the air. 他嗅着空气说：“我闻到煤气味。”The dog sniffed at the bone. 狗嗅着那块骨头。 sniff noun [C]: Have a sniff of this milk and tell me if it's still OK. 你闻一闻这牛奶，再告诉我是不是还可以喝。