ending vs anticlimax

ending and anticlimax both are nouns.

Word	Noun	Adjective	Verb	Adverb
ending	Yes	No	No	No
anticlimax	Yes	No	No	No

As nouns, anticlimax is a hyponym of ending; that is, anticlimax is a word with a more specific, narrower meaning than ending:

Other hyponyms of ending include bathos, epilog, epilogue, epilog, epilogue, peroration, coda, finale.

ending (noun)	anticlimax (noun)
the act of ending something	a change from a serious subject to a disappointing one
the end of a word (a suffix or inflectional ending or final morpheme)	a disappointing decline after a previous rise
the last section of a communication
event whose occurrence ends something
the point in time at which something ends