obliqueness

Obliqueness refers to the quality or state of being oblique: slanted, tilted, or indirect. The term derives from the Latin obliquus meaning slanting, and in English it can describe both physical orientation and figurative manner. In geometry and related fields, obliqueness describes deviations from a reference direction: a line is oblique if it is not perpendicular or parallel to a chosen axis or plane; an oblique projection maps points to a plane using projection lines that are not perpendicular to the plane; an oblique angle is any angle that is not a right angle (though some sources treat oblique angles as non-right angles).

In astronomy and physics, obliqueness appears in phrases such as obliquity, notably the obliquity of the ecliptic, the tilt of Earth's axis relative to its orbit, or the inclination of orbits and axes in other systems. In optics, oblique incidence refers to a beam striking a surface at an angle other than normal incidence. In linguistics and rhetoric, obliqueness can describe indirectness or evasiveness in expression, or grammatical obliques such as syntax that marks oblique cases, though usage varies by language.

The concept is closely related to terms like oblique, slanted, diagonal, and obliquity. Depending on context, obliqueness can emphasize a physical slant, a projection method, a directional bias, or an indirect communicative stance.