freeze-drying vs drying up

freeze-drying and drying up both are nouns.

Word	Noun	Adjective	Verb	Adverb
freeze-drying	Yes	No	No	No
drying up	Yes	No	No	No

As nouns, drying up is a hypernym of freeze-drying; that is, drying up is a word with a broader meaning than freeze-drying:

freeze-drying: a method of drying food or blood plasma or pharmaceuticals or tissue without destroying their physical structure; material is frozen and then warmed in a vacuum so that the ice sublimes
drying up: the process of extracting moisture

Other hypernyms of freeze-drying include dehydration, desiccation, evaporation, freeze, freezing.

freeze-drying (noun)	drying up (noun)
a method of drying food or blood plasma or pharmaceuticals or tissue without destroying their physical structure; material is frozen and then warmed in a vacuum so that the ice sublimes	the process of extracting moisture