Definition of "telling"

But ever since the concept of "hamartia" recurred through Aristotle's Poetics, in an attempt to describe man's ingrained iniquity, our impulse has been to identify a telling defect in those brought suddenly and dramatically low.

2014 October 21, Oliver Brown, “Oscar Pistorius jailed for five years – sport afforded no protection against his tragic fallibilities: Bladerunner's punishment for killing Reeva Steenkamp is but a frippery when set against the burden that her bereft parents, June and Barry, must carry ”, in The Daily Telegraph (Sport)‎

There may he sit and smile, or creep among the ships, or moan and sigh round islands in his great content—the miser lord of wealth in gems and pearls beyond the telling of all fables.

1905, [Edward Plunkett,] Lord Dunsany, The Gods of Pegāna‎, London: Elkin Mathews, […], page 16

"One white man." said Bill, after a brief inspection. "Out on his line, I s'pose, and there's no tellin' when he'll be back. So we won't wait. We'll just serve notice on him."

1922, A[rthur] M[urray] Chisholm, A Thousand a Plate