covering vs fumigation

covering and fumigation both are nouns.

Word	Noun	Adjective	Verb	Adverb
covering	Yes	No	No	No
fumigation	Yes	No	No	No

As nouns, fumigation is a hyponym of covering; that is, fumigation is a word with a more specific, narrower meaning than covering:

covering: the work of applying something
fumigation: the application of a gas or smoke to something for the purpose of disinfecting it

covering (noun)	fumigation (noun)
the act of protecting something by covering it	the application of a gas or smoke to something for the purpose of disinfecting it
the work of applying something
the act of concealing the existence of something by obstructing the view of it
an artifact that covers something else (usually to protect or shelter or conceal it)
a natural object that covers or envelops