E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Fluke.
Hap-hazard. In billiards it means playing for one thing and getting another. Hence an advantage gained by luck more than by skill or judgment. (German, glück, chance, our luck.)
1
We seem to have discovered, as it were by a fluke, a most excellent rule for all future Cabinet arrangements.The Times.