Not Worth A Whistle Meaning

(idiomatic) Worthless or pointless.

Example: 1848, Blanchard Jerrold, The disgrace to the family: A story of social distinctions, page 92:
  We are a set of worthless fellows not worth a whistle.
2010, Yuvraj Ramsaroop, Realizing the American Dream, ISBN 1456837222:
  â€œThe life of a Negro in Mississippi is not worth a whistle,” one of the European newspapers reported.
2011, Jennifer Lawler, Martial Arts For Dummies, ISBN 1118069617:
  This, of course, is ridiculous, as most people can plainly see, but you'd be surprised at how often otherwise intelligent individuals fail to distinguish between what's worth fighting over and what's not worth a whistle.
2015, Ruth Scurr, John Aubrey: My Own Life, ISBN 1448190878, page 257:
  This greatly irritated Mr Hooke and he muttered that Mr Wylde is not worth a whistle'.