WordNet sense 1 (the organ of smell and entrance to the respiratory tract; the prominent part of the face of man or other mammals):

olfactory organ

WordNet sense 2 (a projecting spout from which a fluid is discharged):

nozzle

WordNet sense 3 (search or inquire in a meddlesome way):

intrude, poke, pry, horn in

WordNet sense 4 (catch the scent of; get wind of):

scent, wind, wind

WordNet sense 5 (rub noses):

nuzzle