Anticlimax - a drop, often sudden and unexpected, from a dignified or important idea or situation to a trivial one or a descent from something sublime to something ridiculous. In fiction and drama, this refers to action which is disappointing in contrast to the previous moment of intense interest or anything which follows the climax. The effect may be comic and is often intended to be. According to Samuel Johnson, who first recorded the word, it is “A sentence in which the last part expresses something lower than the first.”
The term comes from the combination of two Greek words: anti, which means “against” or “the reverse of,” and klimax, which means “a ladder” and was derived from klinein meaning “to slope.”
An example of an anticlimax is when the indigent protagonist finds a great amount of money for which (s)he has been intently searching and does nothing with it.