fastness vs lodgement

fastness and lodgement both are nouns.

Word	Noun	Adjective	Verb	Adverb
fastness	Yes	No	No	No
lodgement	Yes	No	No	No

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

Other hyponyms of fastness include lodging, lodgment.

fastness (noun)	lodgement (noun)
a strongly fortified defensive structure	the state or quality of being lodged or fixed even temporarily
a rate (usually rapid) at which something happens
the quality of being fixed in place as by some firm attachment