bilateral Syllabification: (bi·lat·er·al)Pronunciation: /bīˈlatərəl/Translate bilateral | into Italian | into Spanish Definition of bilateral adjective having or relating to two sides; affecting both sides:bilateral hearing is essential for sound location involving two parties, usually countries:the recently concluded bilateral agreements with JapanDerivatives bilaterally adverb bilateral in other Oxford dictionaries Definition of bilateral in the British & World English dictionary