The Collaborative International Dictionary of English v.0.48:

Linnaea borealis \Lin*n[ae]"a bo`re*a"lis\ (l[i^]n*n[=e]"[.a]
   b[=o]`r[-e]*[=a]"l[i^]s) n. [NL. Linnaeus Linn[ae]an + L.
   borealis northern.] (Bot.)
   The twin flower which grows in cold northern climates.
   [1913 Webster] Linnean

The Collaborative International Dictionary of English v.0.48:

Twin \Twin\ (tw[i^]n), a. [OE. twin double, AS. getwinne two and
   two, pl., twins; akin to D. tweeling a twin, G. zwilling,
   OHG. zwiniling, Icel. tvennr, tvinnr, two and two, twin, and
   to AS. twi- two. See Twice, Two.]
   1. Being one of two born at a birth; as, a twin brother or
      sister.
      [1913 Webster]

   2. Being one of a pair much resembling one another; standing
      in the relation of a twin to something else; -- often
      followed by to or with. --Shak.
      [1913 Webster]

   3. (Bot.) Double; consisting of two similar and corresponding
      parts.
      [1913 Webster]

   4. (Crystallog.) Composed of parts united according to some
      definite law of twinning. See Twin, n., 4.
      [1913 Webster]

   Twin boat, or Twin ship (Naut.), a vessel whose deck and
      upper works rest on two parallel hulls.

   Twin crystal. See Twin, n., 4.

   Twin flower (Bot.), a delicate evergreen plant (Linnaea
      borealis) of northern climates, which has pretty,
      fragrant, pendulous flowers borne in pairs on a slender
      stalk.

   Twin-screw steamer, a steam vessel propelled by two screws,
      one on either side of the plane of the keel.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Linnaea borealis
    n 1: creeping evergreen subshrub of the northern parts of Europe
         and Asia with delicate fragrant tubular bell-shaped usually
         pink flowers borne in pairs [syn: twinflower, Linnaea
         borealis]