sniff

1. An instance of sniffing.

   She gave the flowers a quick sniff to check they were real.

2. A quantity of something that is inhaled through the nose
3. A brief perception, or tiny amount.
4. Cocaine.

1. To make a short, audible inhalation, through the nose, as when smelling something.

   I sniffed the meat to see whether it had gone off.

2. To say something while sniffing, for example in case of illness or unhappiness, or in contempt.

   "He's never coming back, is he?" she sniffed while looking at a picture of him.

3. To perceive vaguely

   I can sniff trouble coming from the basement.

4. To be dismissive or contemptuous of something.

   This opportunity is not to be sniffed at.

5. To intercept and analyse packets of data being transmitted over a network.
6. To inhale drugs in powder form (usually cocaine) through the nose.

interjection

A short inhalation sound, sometimes associated with crying.