Unidirectional

[,juːnɪdɪ'rekʃ(ə)n(ə)l;,juːnɪdaɪ-] or [,jʊnɪdə'rɛkʃə

Definition

(adj.) operating or moving or allowing movement in one direction only; 'a unidirectional flow'; 'a unidirectional antenna'; 'a unidirectional approach to a problem' .

Checked by Groves--From WordNet