(countable) An instance of sniffing.

(countable) A quantity of something that is inhaled through the nose.

(countable, colloquial) A brief perception, or tiny amount.

(uncountable, slang) Cocaine.

(transitive, intransitive) To make a short, audible inhalation, through the nose, as when smelling something.

(transitive) To say (something) while sniffing, such as in case of illness or unhappiness, or in contempt.

(transitive) To perceive vaguely.

(intransitive) To pry; to investigate in an interfering manner.

To be dismissive or contemptuous of something; used with at.

(computing) To intercept and analyse packets of data being transmitted over a network.

(slang, chiefly UK) To inhale drugs (usually cocaine) through the nose, usually in powder form.

A short inhalation sound, sometimes associated with crying.