The Collaborative International Dictionary of English v.0.48:

Pompous \Pomp"ous\, a. [F. pompeux, L. pomposus. See Pomp.]
   1. Displaying pomp; stately; showy with grandeur;
      magnificent; as, a pompous procession.
      [1913 Webster]

   2. Ostentatious; pretentious; boastful; vainlorious; as,
      pompous manners; a pompous style. "Pompous in high
      presumption." --Chaucer.
      [1913 Webster]

            he pompous vanity of the old schoolmistress.
                                                  --Thackeray.
      [1913 Webster] -- Pom"ous*ly, adv. -- Pomp"ous*ness,
      n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pompous
    adj 1: puffed up with vanity; "a grandiloquent and boastful
           manner"; "overblown oratory"; "a pompous speech";
           "pseudo-scientific gobbledygook and pontifical hooey"-
           Newsweek [syn: grandiloquent, overblown, pompous,
           pontifical, portentous]
    2: characterized by pomp and ceremony and stately display [syn:
       pompous, ceremonious]