diminished arch vs skeen arch

diminished arch and skeen arch both are nouns.

Word	Noun	Adjective	Verb	Adverb
diminished arch	Yes	No	No	No
skeen arch	Yes	No	No	No

As nouns, diminished arch and skeen arch are synonyms defined as:

diminished arch and skeen arch: an arch whose height is less than half its width

Other synonyms of diminished arch include scheme arch, skene arch.

diminished arch (noun)	skeen arch (noun)
an arch whose height is less than half its width	an arch whose height is less than half its width