adj.
Pronunciation: ˌ yü-ni-d ə - ' rek-shn ə l, -d ī -, -sh ə -n ə l
Function: adjective
Date: 1883
1 : involving, functioning, moving, or responsive in a single direction <a unidirectional microphone>
2 : not subject to change or reversal of direction
– uni · di · rec · tion · al · ly adverb