鉛えん直ちょく

na-adjective, noun which may take the genitive case particle 'no', noun

vertical; perpendicular; upright

Technical term used in physics, engineering, and mathematics to describe a direction exactly aligned with gravity or a line perpendicular to a horizontal plane. More precise than 垂直, which can mean perpendicular to any surface.

• この柱はしらは鉛えん直ちょくに立たっている。

  This pillar stands perfectly vertical.

• 鉛えん直ちょく方ほう向こうの力ちからを計けい算さんしてください。

  Please calculate the force in the vertical direction.