Source : Webster's Revised Unabridged Dictionary (1913)

Chemical \Chem"ic*al\, a.
   Pertaining to chemistry; characterized or produced by the
   forces and operations of chemistry; employed in the processes
   of chemistry; as, chemical changes; chemical combinations.

   {Chemical} {attraction or affinity}. See under {Attraction}.

Chemical \Chem"ic*al\, a.
   Pertaining to chemistry; characterized or produced by the
   forces and operations of chemistry; employed in the processes
   of chemistry; as, chemical changes; chemical combinations.

   {Chemical} {attraction or affinity}. See under {Attraction}.

Chemical \Chem"ic*al\, n.
   A substance used for producing a chemical effect; a reagent.

Source : WordNet®

chemical
     adj 1: relating to or used in chemistry; "chemical engineer";
            "chemical balance" [syn: {chemic}]
     2: of or made from or using substances produced by or used in
        reactions involving atomic or molecular changes; "chemical
        fertilizer"

chemical
     n : produced by or used in a reaction involving changes in atoms
         or molecules