Synonyms of unsound in English:

unsound


See US English definition of unsound

See UK English definition of unsound

adjective

1‘the tower is structurally unsound’

SYNONYMS
rickety, flimsy, shaky, wobbly, unstable, tottery, defective, disintegrating, crumbling, decaying, broken, broken-down, damaged, rotten, ramshackle, insubstantial, jerry-built, unsafe, unreliable, dangerous
Australian, New Zealand informal rumpty
ANTONYMS

sound, strong

2‘this submission appears to us unsound on several grounds’

SYNONYMS
untenable, flawed, defective, faulty, ill-founded, flimsy, weak, shaky, unreliable, questionable, dubious, tenuous, suspect, illogical, irrational, unfounded, ungrounded, unsubstantiated, unsupported, specious, hollow, spurious, false, fallacious, fallible, erroneous, wrong, sophistic, casuistic
informal iffy
British informal dodgy
ANTONYMS

sound, strong

3‘of unsound mind’

SYNONYMS
disordered, diseased, deranged, disturbed, troubled, demented, unstable, unbalanced, unhinged, insane, crazed, distracted
informal touched
ANTONYMS

sane