- not normal or healthy physically or mentally
- not safe, firm, or solid; insecure
- not safe and secure financially
- not based on truth or valid reasoning; not accurate, reliable, sensible, etc.
- light: said of sleep
- Not dependably strong or solid.
- Not physically or mentally healthy.
- Not true or logically valid; fallacious: an unsound conclusion.
(comparative more unsound or unsounder, superlative most unsound or unsoundest)
un- +"Ž sound.