The Collaborative International Dictionary of English v.0.48:

Meretricious \Mer`e*tri"cious\, a. [L. meretricius, from
   meretrix, -icis, a prostitute, lit., one who earns money, i.
   e., by prostitution, fr. merere to earn, gain. See Merit.]
   1. Of or pertaining to prostitutes; having to do with
      harlots; lustful; as, meretricious traffic.
      [1913 Webster]

   2. Resembling the arts of a harlot; alluring by false show;
      gaudily and deceitfully ornamental; tawdry; as,
      meretricious dress or ornaments.
      [1913 Webster]

   3. Deceptive or based on deception; seeming plausible, but
      based on pretense or insincerity; deceptive; misleading;
      insincere; specious; as, meretricious arguments.
      [PJC] -- Mer`e*tri"cious*ly, adv. --
      Mer`e*tri"cious*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

meretriciously
    adv 1: in a meretricious manner; "the boat is meretriciously
           decorated" [syn: meretriciously, flashily]