"the nose," 1858, slang agent noun from sniff (v.).
Entries linking to sniffer
sniff v.
mid-14c., sniffen, intransitive, "draw air through the nose in short breaths," of imitative origin; possibly related to snyvelen (see snivel) or similar Scandinavian words. As an expression of scorn or contempt from 1729. The transitive sense of "draw in with the nose, perceive by smell" is from 1796. In reference to cocaine from 1925. Related: Sniffed; sniffing.