peplum vs peplus

peplum and peplus both are nouns.

Word	Noun	Adjective	Verb	Adverb
peplum	Yes	No	No	No
peplus	Yes	No	No	No

As nouns, peplum and peplus are synonyms defined as:

peplum and peplus: a garment worn by women in ancient Greece; cloth caught at the shoulders and draped in folds to the waist

Other synonyms of peplum include peplos.

peplum (noun)	peplus (noun)
a flared ruffle attached to the waistline of a dress or jacket or blouse	a garment worn by women in ancient Greece; cloth caught at the shoulders and draped in folds to the waist
a garment worn by women in ancient Greece; cloth caught at the shoulders and draped in folds to the waist