Ruheid

Ruheid is a Dutch noun meaning roughness or coarseness. In standard Dutch, the primary spelling is ruwheid, formed from the adjective ruw (rough) with the suffix -heid, which creates abstract nouns. The variant ruheid is rare and generally regarded as a nonstandard spelling or orthographic error.

Usage of ruheid spans physical texture and figurative qualities. It can describe the roughness of a surface, such as wood grain or a mineral facet, as well as the rough character of a conversation or behavior. In technical contexts, speakers more often use ruwheid or the English loanword roughness, especially when discussing surface topography or material texture. When measured, surface roughness is quantified using parameters such as Ra or Rz, which reflect the microscopic irregularities of a surface rather than its chemical composition.

Etymology traces ruwheid to the Dutch adjective ruw, meaning rough, with the suffix -heid forming a noun that expresses a quality. This aligns with cognates in other Germanic languages, such as German Rauhheit and English roughness, reflecting a shared Proto-Germanic heritage.

See also: Roughness, Surface roughness, Texture, Coarseness, Textural analysis.