tactfulness vs delicacy

tactfulness and delicacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
tactfulness	Yes	No	No	No
delicacy	Yes	No	No	No

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

tactfulness: consideration in dealing with others and avoiding giving offense
delicacy: subtly skillful handling of a situation

Other hyponyms of tactfulness include diplomacy, discreetness, finesse, address, savoir-faire, tactfulness.

tactfulness (noun)	delicacy (noun)
consideration in dealing with others and avoiding giving offense	the quality of being beautiful and delicate in appearance
Behavior or actions characterized by careful consideration in dealing with others, to avoid giving offense.	subtly skillful handling of a situation
	lack of physical strength
	slenderness
	lightness in movement or manner
	refined taste; tact
	something considered choice to eat