Merriam-Webster's Collegiate® Dictionary, 11th Edition
SNIFF
I. verb
Etymology: Middle English
Date: 14th century
intransitive verb to draw air audibly up the nose especially for smelling , to show or express disdain or scorn, snoop , nose , transitive verb to smell or take by inhalation through the nose, to utter contemptuously, to recognize or detect by or as if by smelling ,
II. noun
Date: 1767
an act or sound of sniffing, a quantity that is sniffed