rattler

plural rattlers

1. Anything that rattles.
2. USinformalA rattlesnake.

   You watch your step walking out there on the mesa, because in warmer season, the rattlers are up and about, and it's their turf.

   1989 February 5, Kay Whitlock, “Letter from Colorado”, in Gay Community News, volume 16, number 29, page 11

3. rail transportA freight train or, (chiefly UK), a passenger train.

   I'll lay you odds that this old rattler don't get into Shanghai on time.

   1932, Jules Furthman, Shanghai Express, spoken by Sam Salt (Eugene Pallette)

4. colloquialAny decrepit or noisy vehicle, such as a cart, carriage or train.
5. colloquialdatedA loud, inconsiderate talker.
6. colloquialdatedA stunning blow.

   […] laid handsomely out with such a rattler on the nose as nobody could have expected from a casky little man of five-feet-nothing.

   1897, Alexander Montgomery, Five-Skull Island And Other Tales of the Malay Archipelago

7. colloquialdatedAn impudent lie; a whopper.

plural Rattlers

1. A surname.