unidirectional

英 [,juːnɪdɪ'rekʃ(ə)n(ə)l; ,juːnɪdaɪ-] 美[,jʊnɪdə'rɛkʃənl]

1. operating or moving or allowing movement in one direction only;: "a unidirectional flow"; "a unidirectional antenna"; "a unidirectional approach to a problem"