copperplate vs copperplate engraving

copperplate and copperplate engraving both are nouns.

Word	Noun	Adjective	Verb	Adverb
copperplate	Yes	No	No	No
copperplate engraving	Yes	No	No	No

As nouns, copperplate and copperplate engraving are synonyms defined as:

copperplate and copperplate engraving: an engraving consisting of a smooth plate of copper that has been etched or engraved

copperplate (noun)	copperplate engraving (noun)
an engraving consisting of a smooth plate of copper that has been etched or engraved	an engraving consisting of a smooth plate of copper that has been etched or engraved
a print made from an engraved copperplate
a graceful style of handwriting based on the writing used on copperplate engravings