I. “+ transitive verb
Etymology: un- (II) + balance, v.
: to put out of balance
raise taxes and unbalance the budget — Reinhold Niebuhr
everybody's face has a feature or features that unbalance it — Wally Westmore
specifically : to derange mentally
ardor in the cause … threatened to unbalance his mind — J.F.Fulton
II. noun
Etymology: un- (I) + balance, n.
: lack of balance : imbalance ; specifically : mental derangement
the unbalance of even the full-fledged paranoiac is sometimes hard to detect — H.A.Overstreet