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 change in speaking or writing from the impressive or significant to the ludicrous or inconsequential, or an instance of this, as in "He has seen the ravages of war, he has known natural catastrophes, he has been to singles bars" (Woody Allen).