When someone who is asleep snores, they make a loud noise each time they breathe. His mouth was open, and he was snoring. Snore is also a noun. Uncle Arthur, after a loud snore, woke suddenly. to breathe in a noisy way through your mouth and nose while you are asleep (From the sound)
To breathe during sleep with harsh, snorting noises caused by vibration of the soft palate
the act of snoring or producing a snoring sound the rattling noise produced when snoring breathe noisily during one's sleep; "she complained that her husband snores