unidirectional

from WordNet (r) 3.0 (2006)

unidirectional
    adj 1: operating or moving or allowing movement in one direction
           only; "a unidirectional flow"; "a unidirectional
           antenna"; "a unidirectional approach to a problem" [ant:
           {bidirectional}]

from Moby Thesaurus II by Grady Ward, 1.0

43 Moby Thesaurus words for "unidirectional":
      direct, immediate, irreversible, monadal, monadic, one-piece,
      one-sided, one-way, straight, straightaway, straightforward,
      straightway, unbroken, undeviating, uniangulate, unibivalent,
      unibranchiate, unicameral, unicellular, unicuspid, unidentate,
      unidigitate, unidimensional, uniflorous, unifoliate, unifoliolate,
      unigenital, uniglobular, unilateral, unilinear, uniliteral,
      unilobed, unilobular, unimodular, unimolecular, uninterrupted,
      uniocular, unipart, unipartite, unipolar, univalent, univocal,
      unswerving