concertina fold vs flexure

concertina fold and flexure both are nouns.

Word	Noun	Adjective	Verb	Adverb
concertina fold	Yes	No	No	No
flexure	Yes	No	No	No

As nouns, flexure is a hypernym of concertina fold; that is, flexure is a word with a broader meaning than concertina fold:

concertina 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.
flexure: an angular or rounded shape made by folding

Other hypernyms of concertina fold include bend, crease, crimp, fold, plication.

concertina fold (noun)	flexure (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.	act of bending a joint; especially a joint between the bones of a limb so that the angle between them is decreased
	an angular or rounded shape made by folding
	the state of being flexed (as of a joint)