lighthearted vs lightsome

lighthearted and lightsome both are adjectives.

Word	Noun	Adjective	Verb	Adverb
lighthearted	No	Yes	No	No
lightsome	No	Yes	No	No

As adjectives, lighthearted and lightsome are synonyms defined as:

Other synonyms of lighthearted include blithe, blithesome, light-hearted.

lighthearted (adjective)	lightsome (adjective)
carefree and happy and lighthearted	carefree and happy and lighthearted
	moving easily and quickly; nimble