Definition of "ailing"

When you're well enough off so's you don't have to fret about anything but your heft or your diseases you begin to get queer, I suppose. And the queerer the cure for those ailings the bigger the attraction. A place like the Right Livers' Rest was bound to draw freaks, same as molasses draws flies.

1913, Joseph C. Lincoln, chapter 5, in Mr. Pratt's Patients

Based on the successful Class 59 but with a much more modern engine, what was to become the Class 66 was designed to replace much of the company's elderly and ailing locomotive fleet.

2021 February 24, “Fleet News: Class 66 history”, in RAIL, number 925, page 27