soft spot vs tenderness

soft spot and tenderness both are nouns.

Word	Noun	Adjective	Verb	Adverb
soft spot	Yes	No	No	No
tenderness	Yes	No	No	No

As nouns, tenderness is a hypernym of soft spot; that is, tenderness is a word with a broader meaning than soft spot:

Other hypernyms of soft spot include affection, affectionateness, fondness, heart, philia, warmheartedness, warmness.

soft spot (noun)	tenderness (noun)
a place of especial vulnerability	a tendency to express warm and affectionate feeling
any membranous gap between the bones of the cranium in an infant or fetus	a feeling of concern for the welfare of someone (especially someone defenseless)
a sentimental affection	a positive feeling of liking
	warm compassionate feelings
	a pain that is felt (as when the area is touched)