Yksisuuntaiset

Yksisuuntaiset is a Finnish adjective meaning unidirectional or one-way. It describes things that operate, move, or flow in a single direction and not in reverse. The word is used in both everyday language and technical terms; grammatically it adapts as yksisuuntaiset when modifying plural nouns.

In everyday Finnish, it is common in traffic discussions about one-way streets or routes: yksisuuntaiset liikennejärjestelmät, yksisuuntainen katu. In engineering and science, it denotes directional bias: yksisuuntaiset venttiilit (one-way valves), yksisuuntaiset virtaukset (unidirectional flows), or yksisuuntaiset signaalit (unidirectional signals).

In biology, the term is used for processes such as unidirectional transport of cellular cargo along cytoskeletal tracks, typically driven by motor proteins that move toward a defined end of the filament. In physics and electronics, it applies to phenomena or devices that favor a single direction, for example diodes or non-reciprocal wave propagation.

Etymology: from yksikk- 'one' + suunta 'direction' + -inen/-iset, forming 'one-directional' or 'unidirectional'. The concept is contrasted with kaksisuuntainen (bidirectional).