anticlimax
an·ti·cli·max
/ˌænˌtaıˈklaıˌmæks/ noun , pl -max·es
: something that is much less exciting or dramatic than it was expected to be : a dull or disappointing ending or result
[ count ] The last chapter of the book was an anticlimax.
[ noncount ] The movie ended in anticlimax.
an·ti·cli·mac·tic /ˌænˌtaıˌklaıˈmæktık/ adj
The last chapter of the book was anticlimactic.
The trial was anticlimactic, since it ended without a verdict.
