出典:Wiktionary
From Middle English soundenes, soundnes, from 古期英語 *sundnes, *ġesundnes (attested in onsundnes), from Proto-West Germanic *sundnassī (“soundness, health”); equivalent to sound + -ness. Cognate with West Frisian sûnens (“soundness, health”), Middle Low German suntnisse (“soundness, health”), Middle High German suntnisse (“soundness, health”), German Gesundnis (“health”).
soundness (countable かつ uncountable, 複数形 soundnesses)