rashness vs heedlessness

rashness and heedlessness both are nouns.

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

As nouns, rashness and heedlessness are synonyms defined as:

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

Other synonyms of rashness include mindlessness.

rashness (noun)	heedlessness (noun)
the trait of giving little thought to danger	the trait of forgetting or ignoring your responsibilities
the trait of acting rashly and without prudence	the trait of acting rashly and without prudence
	a lack of attentiveness (as to children or helpless people)