IPA: /ˈsaʊndnəs/
KK: /ˈsaʊndnəs/
The quality or condition of being in good health, strong, or reliable.
The soundness of the building was confirmed by the engineers after their inspection.
Soundness → It is formed from "sound" (from Old English *sund*, meaning healthy or safe) and "-ness" (meaning the state or quality of). The word "soundness" refers to the quality of being sound, healthy, or reliable.
Think of 'sound' meaning healthy or safe, and remember that 'soundness' describes the state of being healthy or reliable.