Source : Webster's Revised Unabridged Dictionary (1913)

Lex \Lex\ (l[e^]ks), n.; pl. {Leges} (l[=e]"j[=e]z). [L. See
   {Legal}.]
   Law; as, lex talionis, the law of retaliation; lex terr[ae],
   the law of the land; lex fori, the law of the forum or court;
   lex loci, the law of the place; lex mercatoria, the law or
   custom of merchants.

Source : Free On-Line Dictionary of Computing

Lex
     
        1.  A {lexical analyser} generator for {Unix} and its
        input language.  There is a {GNU} version called {flex} and a
        version written in, and outputting, {SML/NJ} called {ML-lex}.
        A version, by David Poole at Montana has been retargeted to
        {Turbo Pascal}, {(ftp://iecc.com/pub/file/lyprg.zip)}.
     
        ["Lex - A Lexical Analyzer Generator", M.E. Lesk, CS TR 39,
        Bell Labs, Oct 1975].
     
        2.  The lexical specification
        language for {COPS}.
     
        ["Metalanguages of the Compiler Production System COPS",
        J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed
        W. Henhapl, Tech Hochs Darmstadt 1978, pp.122-159].
     
        (2000-11-15)