Merriam-Webster's Collegiate® Dictionary, 11th Edition
RUSTLE
I. verb (rustled; rustling)
Etymology: Middle English rustelen
Date: 14th century
intransitive verb to make or cause a rustle,
2. to act or move with energy or speed, to forage food, to steal cattle, transitive verb to cause to rustle,
2. to obtain by one's own exertions, forage , to steal (as livestock) especially from a farm or ranch, rustler noun
II. noun
Date: 1759
a quick succession or confusion of small sounds