Real Dictionary

bathos
uncountable noun: In literary criticism, bathos is a sudden change in speech or writing from a serious or important subject to a ridiculous or very ordinary one.

bathos in American English
an abrupt, often ludicrous change from the lofty to the ordinary or trivial in writing or speech; unintentional anticlimax
noun: a ludicrous descent from the exalted or lofty to the commonplace; anticlimax

bathos in British English
noun: a sudden ludicrous descent from exalted to ordinary matters or style in speech or writing