giddiness vs lightness

giddiness and lightness both are nouns.

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

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

Other hyponyms of giddiness include lightsomeness.

giddiness (noun)	lightness (noun)
an impulsive scatterbrained manner	the trait of being lighthearted and frivolous
a reeling sensation; a feeling that you are about to fall	the visual effect of illumination on objects or scenes as created in pictures
	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