anticlimax

an·ti·cli·max (ăn'tē-klī'măks', ăn'tī-)
n.

1. A decline viewed in disappointing contrast with a previous rise: the anticlimax of a brilliant career.
2. Something trivial or commonplace that concludes a series of significant events: After a week of dramatic negotiations, all that followed was anticlimax.
3. 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).

anticlimactic an'ti·cli·mac'tic (-klī-măk'tĭk) adj.
anticlimactically an'ti·cli·mac'ti·cal·ly adv.