( n. )
A falling in of the surface; a sinking below its true place; a cavity or hollow; as, roughness consists in little protuberances and depressions.
( n. )
A falling in of the surface; a sinking below its true place; a cavity or hollow; as, roughness consists in little protuberances and depressions.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012