Source : Webster's Revised Unabridged Dictionary (1913)

Grandiloquent \Gran*dil"o*quent\, a. [L. grandis grand + logui
   to speak.]
   Speaking in a lofty style; pompous; bombastic.

Source : WordNet®

grandiloquent
     adj 1: lofty in style; "he engages in so much tall talk, one never
            really realizes what he is saying" [syn: {magniloquent},
             {tall}]
     2: puffed up with vanity; "a grandiloquent and boastful
        manner"; "overblown oratory"; "a pompous speech";
        "pseudo-scientific gobbledygook and pontifical hooey"-
        Newsweek [syn: {overblown}, {pompous}, {pontifical}, {portentous}]