Black's Law Dictionary (2nd edition)dictionaries

Crank

A term vulgarly applled to a person of eccentric, ill-regulated, and un-practical mental habits; a person half-craz-ed; a monomaniac; not necessarily equiva-lent to “insane pereon,” “lunatic,” or auy other term descriptive of complete mental derangement, and uot carrying any implica-tion of homicidal mania, walker v. Tri-bune Co. (C. C.) 29 Fed. 827

Source: Black’s Law Dictionary 2nd Ed (1910)