upending vs overturn

upending and overturn both are nouns.

Word	Noun	Adjective	Verb	Adverb
upending	Yes	No	No	No
overturn	Yes	No	Yes	No

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

Other hyponyms of upending include turnover, upset.

upending (noun)	overturn (noun)
turning upside down; setting on end	the act of upsetting something
	an improbable and unexpected victory

upending (verb)	overturn (verb)
	change radically
	rule against
	cancel officially
	turn from an upright or normal position
	cause to overturn from an upright or normal position
	cause the downfall of; of rulers