'Rustler' definitions:

Definition of 'rustler'

(from WordNet)
noun
Someone who steals livestock (especially cattle) [syn: rustler, cattle thief]

Definition of 'Rustler'

From: GCIDE
  • Rustler \Rus"tler\, n.
  • 1. One who, or that which, rustles. [1913 Webster]
  • 2. A bovine animal that can care for itself in any circumstances; also, an alert, energetic, driving person. [Slang, Western U.S.] [1913 Webster]