The Collaborative International Dictionary of English v.0.48:

Rosemary \Rose"ma*ry\, n. [OE. rosmarine, L. rosmarinus; ros dew
   (cf. Russ. rosa, Lith. rasa, Skr. rasa juice) + marinus
   marine: cf. F. romarin. In English the word has been changed
   as if it meant the rose of Mary. See Marine.]
   A labiate shrub (Rosmarinus officinalis) with narrow
   grayish leaves, growing native in the southern part of
   France, Spain, and Italy, also in Asia Minor and in China. It
   has a fragrant smell, and a warm, pungent, bitterish taste.
   It is used in cookery, perfumery, etc., and is an emblem of
   fidelity or constancy.
   [1913 Webster]

         There's rosemary, that's for remembrance. --Shak.
   [1913 Webster]

   Marsh rosemary.
   (a) A little shrub (Andromeda polifolia) growing in cold
       swamps and having leaves like those of the rosemary.
   (b) See under Marsh.

   Rosemary pine, the loblolly pine. See under Loblolly.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rosemary
    n 1: widely cultivated for its fragrant grey-green leaves used
         in cooking and in perfumery [syn: rosemary, Rosmarinus
         officinalis]
    2: extremely pungent leaves used fresh or dried as seasoning for
       especially meats