sniff

[MikeLigalig.com]

sniff

sniff [snif]
verb (past and past participle sniffed, present participle sniff·ing, 3rd person present singular sniffs)

1.  transitive and intransitive verb breathe in through nose: to breathe in through the nose quickly, briefly, and audibly, e.g. in smelling something or to prevent mucus from dripping, or smell something by breathing in quickly
2.  transitive verb suspect something: to have a suspicion of something, especially something bad
sniff trouble

noun (plural sniffs)
1.  brief inhalation: an instance or sound of sniffing
2.  suspicion: a hint or suspicion, especially of something bad

[14th century. An imitation of the sound]