bas relief vs basso relievo

bas relief and basso relievo both are nouns.

Word	Noun	Adjective	Verb	Adverb
bas relief	Yes	No	No	No
basso relievo	Yes	No	No	No

As nouns, bas relief and basso relievo are synonyms defined as:

bas relief and basso relievo: a sculptural relief in which forms extend only slightly from the background; no figures are undercut

Other synonyms of bas relief include basso rilievo, low relief.

bas relief (noun)	basso relievo (noun)
a sculptural relief in which forms extend only slightly from the background; no figures are undercut	a sculptural relief in which forms extend only slightly from the background; no figures are undercut