to draw air audibly up the nose; to snuff; -- sometimes done as a gesture of suspicion, offense, or contempt.-to draw in with the breath through the nose; as, to sniff the air of the country.-to perceive as by sniffing; to snuff, to scent; to smell; as, to sniff danger.-the act of sniffing; perception by sniffing; that which is taken by sniffing; as, a sniff of air.