z-fold vs plication

z-fold and plication both are nouns.

Word	Noun	Adjective	Verb	Adverb
z-fold	Yes	No	No	No
plication	Yes	No	No	No

As nouns, plication is a hypernym of z-fold; that is, plication is a word with a broader meaning than z-fold:

z-fold: a continuous parallel folding in an accordion-like fashion, that is with folds alternatively made to the front and back in zig-zag folds.
plication: an angular or rounded shape made by folding

Other hypernyms of z-fold include bend, crease, crimp, flexure, fold.

z-fold (noun)	plication (noun)
a continuous parallel folding in an accordion-like fashion, that is with folds alternatively made to the front and back in zig-zag folds.	the act of folding in parallel folds
	an angular or rounded shape made by folding