scupper vs endanger

scupper is a noun but endanger is not a noun.

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

As verbs, scupper and endanger are synonyms defined as:

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

Other synonyms of scupper include expose, peril, queer.

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

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