endanger vs scupper

endanger is not a noun while scupper is a noun.

Word	Noun	Adjective	Verb	Adverb
endanger	No	No	Yes	No
scupper	Yes	No	Yes	No

As verbs, endanger and scupper are synonyms defined as:

endanger and scupper: put in a dangerous, disadvantageous, or difficult position

Other synonyms of endanger include expose, peril, queer.

endanger (noun)	scupper (noun)
	drain that allows water on the deck of a vessel to flow overboard

endanger (verb)	scupper (verb)
put in a dangerous, disadvantageous, or difficult position	put in a dangerous, disadvantageous, or difficult position
pose a threat to; present a danger to	wait in hiding to attack