- diseased, weak, or unstable: of unsound mind
- unreliable or fallacious: unsound advice
- lacking solidity, strength, or firmness: unsound foundations
- of doubtful financial or commercial viability: an unsound enterprise
WordReference Random House Learner's Dictionary of American English © 2026
un•sound /ʌnˈsaʊnd/USA pronunciation
adj., -er, -est.
WordReference Random House Unabridged Dictionary of American English © 2026- not sound;
unhealthy or diseased, as the body or mind. - not solid or firm, as foundations.
- not valid;
full of false arguments:an unsound argument. - easily broken;
light:unsound sleep. - not financially strong or secure:an unsound investment.
un•sound
(un sound′),USA pronunciation adj., -er, -est.
un•sound′ly, adv.
un•sound′ness, n.
- not sound;
unhealthy, diseased, or disordered, as the body or mind. - decayed or impaired, as timber or foods;
defective. - not solid or firm, as foundations.
- not well-founded or valid;
fallacious:an unsound argument. - easily broken;
light:unsound slumber. - not financially strong;
unreliable:an unsound corporation.
- 1275–1325; Middle English; see un-1, sound2
un•sound′ness, n.
- 1. infirm, sick, ill, unhealthy. 2. rotten, unwholesome. 4. false, erroneous, faulty.
Collins Concise English Dictionary © HarperCollins Publishers::
unsound /ʌnˈsaʊnd/ adj
'unsound' also found in these entries (note: many are not synonyms or translations):
cronk
- fallacy
- guardian
- receiver
- screw
- shonky
- sophist
- sophistry
- unbalanced
- vicious
- wildcat
- ailing
- bad
- bucket shop
- crack
- cranky
- crazy
- fallacious
- ill
- illogical
- infirm
- lunatic
- unhealthy
- unsoundable
- unsounded
- unsounding
- untenable
- weak
- wildcatter
- sick
- sophister
- stultify