an·ti·cli·max (?n't?-kl?'m?ks', ?n't?-)
n.
A decline viewed in disappointing contrast with a previous rise: the anticlimax of a brilliant career.
Something trivial or commonplace that concludes a series of significant events: After a week of dramatic negotiations, all that followed was anticlimax.
A sudden descent in speaking or writing from the impressive or significant to the ludicrous or inconsequential, or an instance of it: "Waggish non-Yale men never seem weary of calling 'for God, for Country and for Yale' the outstanding single anticlimax in the English language" (Time).