Source : Webster's Revised Unabridged Dictionary (1913)

Vapid \Vap"id\, a. [L. vapidus having lost its lire and spirit,
   vapid; akin to vappa vapid wine, vapor vapor. See {Vapor}.]
   Having lost its life and spirit; dead; spiritless; insipid;
   flat; dull; unanimated; as, vapid beer; a vapid speech; a
   vapid state of the blood.

         A cheap, bloodless reformation, a guiltless liberty,
         appear flat and vapid to their taste.    --Burke.
   -- {Vap"id*ly}, adv. -- {Vap"id*ness}, n.

Source : WordNet®

vapid
     adj 1: lacking taste or flavor or tang; "a bland diet"; "insipid
            hospital food"; "flavorless supermarket tomatoes";
            "vapid beer"; "vapid tea" [syn: {bland}, {flat}, {flavorless},
             {flavourless}, {insipid}, {savorless}, {savourless}]
     2: lacking significance or liveliness or spirit or zest; "a
        vapid conversation"; "a vapid smile"; "a bunch of vapid
        schoolgirls"