Entry Word: unsound

Function: adjective

Meaning: 1 having or showing a very abnormal or sick state of mind <disgruntled relatives had to prove that the woman was of unsound mind when she made her will> — see insane 1
2 not being in agreement with what is true <an unsound and dangerous assumption> — see false 1
3 not using or following good reasoning <it is clearly unsound to argue that just because it's raining right now, it will rain for the rest of our vacation> — see illogical
4 temporarily suffering from a disorder of the body <an unsound horse that will have to be disqualified from the race> — see sick 1