timidness vs fearfulness

timidness and fearfulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
timidness	Yes	No	No	No
fearfulness	Yes	No	No	No

As nouns, fearfulness is a hypernym of timidness; that is, fearfulness is a word with a broader meaning than timidness:

timidness: fear of the unknown or unfamiliar or fear of making decisions
fearfulness: an emotion experienced in anticipation of some specific pain or danger (usually accompanied by a desire to flee or fight)

Other hypernyms of timidness include fear, fright.

timidness (noun)	fearfulness (noun)
fear of the unknown or unfamiliar or fear of making decisions	the trait of being afraid
	an emotion experienced in anticipation of some specific pain or danger (usually accompanied by a desire to flee or fight)