A theoretical line (physically or mentally) followed from a point of origin or towards a destination. May be relative (e.g. up, left, outbound, dorsal), geographical (e.g. north), rotational (e.g. clockwise), or with respect to an object or location (e.g. toward Boston).

plural of directional

Indicating direction. / Of or relating to guidance or help.

Something that indicates direction, such as a vehicle's turn signal.

plural of direction

Instructions for how to reach a destination or how to do something

Providing adequate direction; directive

plural of directness

(physics, electrical engineering) A measure of the performance of an antenna compared to an isotropic antenna; the ratio of the maximum value of radiation intensity to the average radiation intensity.

Able to be directed.