The Collaborative International Dictionary of English v.0.48:

Herbal \Herb"al\, a.
   Of or pertaining to herbs. --Quarles.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Herbal \Herb"al\, n.
   1. A book containing the names and descriptions of plants.
      --Bacon.
      [1913 Webster]

   2. A collection of specimens of plants, dried and preserved;
      a hortus siccus; an herbarium. --Steele.
      [1913 Webster]

WordNet (r) 3.0 (2006):

herbal
    adj 1: of or relating to herbs; "herbal tea, herbal medicine"
    n 1: tea-like drink made of leaves of various herbs [syn: herb
         tea, herbal tea, herbal]