degaussing vs demagnetisation

degaussing and demagnetisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
degaussing	Yes	No	No	No
demagnetisation	Yes	No	No	No

As nouns, demagnetisation is a hypernym of degaussing; that is, demagnetisation is a word with a broader meaning than degaussing:

degaussing: the process of making a (steel) ship's hull nonmagnetic by producing an opposing magnetic field
demagnetisation: the process of removing magnetization

Other hypernyms of degaussing include demagnetization.

degaussing (noun)	demagnetisation (noun)
the process of making a (steel) ship's hull nonmagnetic by producing an opposing magnetic field	the process of removing magnetization