Home › Words › M › mountainousnessmountainousnessmountainousness means the quality of being mountainous.EtymologyFrom mountainous + -ness (“a state of being”, suffix forming a noun).nounThe quality of being mountainous.e.g.“[…] according to Polybius, the Arcadians, owing to the mountainousness of their country, and the severity of the weather, were very rugged and unsociable.” — 1808, Allan Ramsay, “An Inquiry into the Propriety of the Rules Prescribed for Pastoral Poetry”, in The Gentle Shepherd, a Pastoral Comedy; with Illustrations of the Scenary: […], volume 1, Edinburgh,Definitions & examples from Wiktionary (CC BY-SA 3.0).