heedlessness vs mindlessness

heedlessness and mindlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
heedlessness	Yes	No	No	No
mindlessness	Yes	No	No	No

As nouns, heedlessness and mindlessness are synonyms defined as:

heedlessness and mindlessness: the trait of acting rashly and without prudence

Other synonyms of heedlessness include rashness.

heedlessness (noun)	mindlessness (noun)
the trait of forgetting or ignoring your responsibilities	the trait of acting rashly and without prudence
the trait of acting rashly and without prudence	total lack of meaning or ideas
a lack of attentiveness (as to children or helpless people)