directionally

Directionally is an adverb formed from the adjective directional. It describes something related to direction or performed in a way that depends on orientation. In scientific and technical writing, directionally is used to indicate that a property or effect varies with direction rather than being uniform in all directions.

Common contexts include directionally dependent phenomena, such as anisotropic materials, directionally sensitive sensors, and signals that propagate more strongly along a particular axis. A radio antenna, for example, can be more receptive in the direction of a signal source, rendering its reception directionally biased. In geography or navigation, paths or flows may be described as directionally constrained when their behavior differs by direction.

Etymology and usage notes: directionally derives from direction plus the suffix -al to form directional, with -ly creating the adverb. It is widely accepted in modern English and appears across physics, engineering, and data analysis to specify directional dependence or orientation.

Related terms include directional, direction, anisotropy, isotropy, vector, and gradient.