lightness vs giddiness

lightness and giddiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
lightness	Yes	No	No	No
giddiness	Yes	No	No	No

As nouns, giddiness is a hypernym of lightness; that is, giddiness is a word with a broader meaning than lightness:

Other hypernyms of lightness include silliness.

lightness (noun)	giddiness (noun)
the trait of being lighthearted and frivolous	an impulsive scatterbrained manner
the visual effect of illumination on objects or scenes as created in pictures	a reeling sensation; a feeling that you are about to fall
the property of being comparatively small in weight
having a light color
the gracefulness of a person or animal that is quick and nimble
a feeling of joy and pride