sniff

Concise Oxford English Dictionary © 2008 Oxford University Press:
sniff/snɪf/

▶verb

• 1 draw air audibly through the nose.

• 2 (sniff around/round) informal investigate something covertly.

  ■ (sniff something out) informal discover something by investigation.

▶noun

• 1 an act or sound of sniffing.

• 2 informal a hint or sign.

– phrases
not to be sniffed at informal worth having or considering.

– derivatives
sniffer noun.

– origin ME: imitative.