Source : Webster's Revised Unabridged Dictionary (1913)

Holm \Holm\, n. [OE., prob. from AS. holen holly; as the holly
   is also called holm. See {Holly}.] (Bot.)
   A common evergreen oak, of Europe ({Quercus Ilex}); -- called
   also {ilex}, and {holly}.

Ilex \I"lex\, n. [L., holm oak.] (Bot.)
   (a) The holm oak ({Quercus Ilex}).
   (b) A genus of evergreen trees and shrubs, including the
       common holly.

Source : WordNet®

Quercus ilex
     n : evergreen oak of southern Europe having leaves somewhat
         resembling those of holly; yields a hard wood [syn: {holm
         oak}, {holm tree}, {holly-leaved oak}, {evergreen oak}]