disregard vs inattention

disregard and inattention both are nouns.

Word	Noun	Adjective	Verb	Adverb
disregard	Yes	No	Yes	No
inattention	Yes	No	No	No

As nouns, inattention is a hypernym of disregard; that is, inattention is a word with a broader meaning than disregard:

disregard (noun)	inattention (noun)
willful lack of care and attention	lack of attention
lack of attention and due care

disregard (verb)	inattention (verb)
give little or no attention to
bar from attention or consideration
refuse to acknowledge