A rule with a short perpendicular crosspiece at one end, used by draughtsmen to draw parallel lines.
A sex position whereby the receiving partner lies on the back with knees up and legs apart while the penetrating partner lies on either side perpendicular to the receiver, with the penetrating partner's hips under the arch formed by receiver's legs.
A measuring rod thirty-six inches (one yard) long.
A standard to which other measurements or comparisons are judged.