(adj): eaten away as by acid or oxidation
(adj): damaged by decay; hence unsound and useless
(adj): vs. sound) -- (not sound financially
(adj): not financially safe or secure
(adj): involving substantial risk
(adj): outside the bounds of legitimate or ethical business practices
(adj): containing or based on a fallacy
(adj): vs. valid) -- (having no cogency or legal force
(adj): suffering from severe mental illness
(adj): vs. sane) -- (afflicted with or characteristic of mental derangement
(adj): physically unsound or diseased
(adj): vs. healthy) -- (not in or exhibiting good health in body or mind
(adj): of e.g. advice
(adj): vs. reliable), undependable (vs. dependable) -- (not worthy of reliance or trust
