truncation vs shortening

truncation and shortening both are nouns.

Word	Noun	Adjective	Verb	Adverb
truncation	Yes	No	No	No
shortening	Yes	No	No	No

As nouns, shortening is a hypernym of truncation; that is, shortening is a word with a broader meaning than truncation:

truncation (noun)	shortening (noun)
the act of cutting short	act of decreasing in length
the replacement of an edge or solid angle (as in cutting a gemstone) by a plane (especially by a plane that is equally inclined to the adjacent faces)	fat such as butter or lard used in baked goods
the property of being truncated or short