a pathological condition resulting from a reaction to or an excessive use of cinchona bark or any of its derivatives, as quinine: it is characterized by headache, ringing in the ears, deafness, etc.
See cinchonism in American Heritage Dictionary 4
noun
A pathological condition resulting from an overdose of cinchona bark or its alkaloid derivatives and marked by headache, dizziness, hearing loss, and ringing in the ears.