[n] a change from a serious subject to a disappointing one
[n] triteness or triviality of style
[n] insincere pathos
anticlimax - (4 syllables), mawkishness - (3 syllables)
\Ba"thos\, n. [Gr. ? depth, fr. ? deep.] (Rhet.) A ludicrous descent from the elevated to the low, in writing or speech; anticlimax.