halftone engraving vs halftone

halftone engraving and halftone both are nouns.

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

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

halftone engraving and halftone: an engraving used to reproduce an illustration

Other synonyms of halftone engraving include photoengraving.

halftone engraving (noun)	halftone (noun)
an engraving used to reproduce an illustration	an engraving used to reproduce an illustration
	a print obtained from photoengraving