Webster's 1828 Dictionary
SOUNDNESS
n. 1. Wholeness; entireness; an unbroken, unimpaired or undecayed state; as the soundness of timber, of fruit, of the teeth, of a limb, etc.
2. An unimpaired state of an animal or vegetable body; a state in which the organs are entire and regularly perform their functions. We say, the soundness of the body, the soundness of the constitution, the soundness of health.
3. Firmness; strength; solidity; truth; as soundness of reasoning or argument, of doctrine or principles.
4. Truth; rectitude; firmness; freedom from error or fallacy; orthodoxy; as soundness of faith.
Webster's 1913 Dictionary
SOUNDNESS
SOUNDNESS Sound "ness, n.
Defn: The quality or state of being sound; as, the soundness of timber, of fruit, of the teeth, etc. ; the soundness of reasoning or argument; soundness of faith.
Syn. -- Firmness; strength; solidity; healthiness; truth; rectitude.
Sanseido Wisdom Dictionary
soundness
s ó und ness 名詞 U 頑強さ, 安全性 ; (財政などの )健全性 ; (判断などの )正当性, 正しさ ; (眠りが )深いこと .