Source : Webster's Revised Unabridged Dictionary (1913)

Lexical \Lex"ic*al\ (-[i^]*kal), a.
   Of or pertaining to a lexicon, to lexicography, or words;
   according or conforming to a lexicon. -- {Lex"ic*al*ly}, adv.

Source : WordNet®

lexical
     adj 1: of or relating to words; "lexical decision task"
     2: of or relating to dictionaries