yard goods vs piece goods

yard goods and piece goods both are nouns.

Word	Noun	Adjective	Verb	Adverb
yard goods	Yes	No	No	No
piece goods	Yes	No	No	No

As nouns, yard goods and piece goods are synonyms defined as:

yard goods and piece goods: merchandise in the form of fabrics sold by the yard

yard goods (noun)	piece goods (noun)
merchandise in the form of fabrics sold by the yard	merchandise in the form of fabrics sold by the yard