The Collaborative International Dictionary of English v.0.48:

Romantic \Ro*man"tic\, a. [F. romantique, fr. OF. romant. See
   Romance.]
   1. Of or pertaining to romance; involving or resembling
      romance; hence, fanciful; marvelous; extravagant; unreal;
      as, a romantic tale; a romantic notion; a romantic
      undertaking.
      [1913 Webster]

            Can anything in nature be imagined more profane and
            impious, more absurd, and undeed romantic, than such
            a persuasion?                         --South.
      [1913 Webster]

            Zeal for the good of one's country a party of men
            have represented as chimerical and romantic.
                                                  --Addison.
      [1913 Webster]

   2. Entertaining ideas and expectations suited to a romance;
      as, a romantic person; a romantic mind.
      [1913 Webster]

   3. Of or pertaining to the style of the Christian and popular
      literature of the Middle Ages, as opposed to the classical
      antique; of the nature of, or appropriate to, that style;
      as, the romantic school of poets.
      [1913 Webster]

   4. Characterized by strangeness or variety; suggestive of
      adventure; suited to romance; wild; picturesque; --
      applied to scenery; as, a romantic landscape.
      [1913 Webster]

   Syn: Sentimental; fanciful; fantastic; fictitious;
        extravagant; wild; chimerical. See Sentimental.
        [1913 Webster]

   The romantic drama. See under Drama.
      [1913 Webster]

WordNet (r) 3.0 (2006):

romantic
    adj 1: belonging to or characteristic of Romanticism or the
           Romantic Movement in the arts; "romantic poetry" [syn:
           romantic, romanticist, romanticistic]
    2: expressive of or exciting sexual love or romance; "her
       amatory affairs"; "amorous glances"; "a romantic adventure";
       "a romantic moonlight ride" [syn: amatory, amorous,
       romantic]
    3: not sensible about practical matters; idealistic and
       unrealistic; "as quixotic as a restoration of medieval
       knighthood"; "a romantic disregard for money"; "a wild-eyed
       dream of a world state" [syn: quixotic, romantic, wild-
       eyed]
    n 1: a soulful or amorous idealist
    2: an artist of the Romantic Movement or someone influenced by
       Romanticism [syn: romanticist, romantic] [ant:
       classicist]

Moby Thesaurus II by Grady Ward, 1.0:

130 Moby Thesaurus words for "romantic":
   Don Quixote, Quixote, Utopian, abstract, absurd, adoring,
   affectionate, airy, allegoric, amorous, aroused, autistic,
   bathetic, beery, chimerical, cloying, conjugal, crackpot, created,
   daydreamer, demonstrative, dereistic, devoted, dreamer,
   dreamer of dreams, emotional, enthusiast, escapist, exotic,
   extravagant, fabulous, faithful, fancied, fanciful, fantasized,
   fantastic, fictional, fictitious, filial, fond, fresh, glamorous,
   gooey, gushing, husbandly, ideal, idealist, idealistic, idealized,
   idyllic, illusory, imaginary, imagined, impassioned, impractical,
   in the clouds, invented, languishing, legendary, libidinous,
   lotus-eater, lovelorn, lovesick, lovesome, loving, lustful, mad,
   made-up, maternal, maudlin, mawkish, melting, mushy, mythic,
   mythical, mythological, mythopoeic, mythopoetic, namby-pamby,
   nostalgic, nostomanic, otherworldly, oversentimental,
   oversentimentalized, parabolic, parental, passionate, paternal,
   picturesque, poetic, prophet, quixotic, rhapsodist, romancer,
   romancing, romanesque, romanticist, romanticized, saccharine,
   sappy, seer, sentimental, sentimentalist, sentimentalized, sloppy,
   slushy, soft, soppy, starry-eyed, sticky, storybook, strange,
   sugary, sweet, tear-jerking, teary, tender, transcendental,
   transmundane, unpractical, unrealistic, utopian, utopianist,
   utopianizer, uxorious, visionary, wifely, wild, wish-fulfilling,
   wishful thinker