sconcheon arch vs scoinson arch

sconcheon arch and scoinson arch both are nouns.

Word	Noun	Adjective	Verb	Adverb
sconcheon arch	Yes	No	No	No
scoinson arch	Yes	No	No	No

As nouns, sconcheon arch and scoinson arch are synonyms defined as:

sconcheon arch and scoinson arch: an arch that supports part of the wall

sconcheon arch (noun)	scoinson arch (noun)
an arch that supports part of the wall	an arch that supports part of the wall