[f. CRANK sb.2 5 + -ERY.: cf. foolery, knavery.] The characteristics of a ‘crank’; crack-brainedness, enthusiastic eccentricity.

1

1884.  Times, 15 Oct., 3/1. The assassin of President Garfield was a crank, and crankery ranges all the way from dangerous approach to insanity and violence to the one-idead fanatics in pseudo-scientific research [etc.].

2

1890.  Sat. Rev., 19 April, 481/2. The thoughts and words of a ‘crank,’ often very amusing and interesting in themselves, and as a study of crankery.

3