From Longman Dictionary of Contemporary Englishsnufflesnuf‧fle /ˈsnʌfəl/ verb [intransitive] BREATHEto breathe noisily through your nose, sometimes because you are crying The little boys snuffled in their sleep.→ See Verb table
Examples from the Corpus
snuffle• Before I unlocked it I could hear him snuffling and whimpering excitedly.• It was revolting to see these half-starved creatures snuffling around behind the houses or along the river-bank in search of excrement.• He never saw his pursuer, though occasionally he heard it snuffling behind him.• She'd thought it was Anna, snuffling in her sleep or from grief.• He started making snuffling noises.• When he gets really impatient, his keeper says, he starts rolling his head around or making snuffling noises.• It was a wonderful snuffling sound.Origin snuffle (1500-1600) Perhaps from Dutch snuffelen