What is "to rustle up"

Rustle \Rus"tle\, v. i. [imp. & p. p. Rustled; p. pr. & vb. n. Rustling.] [AS. hristlan to rustle; or cf. Sw. rusta to stir, make a riot, or E. rush, v.]

1. To make a quick succession of small sounds, like the rubbing or moving of silk cloth or dry leaves.

   He is coming; I hear his straw rustle.
   --Shak.

   Prouder than rustling in unpaid-for silk.
   --Shak.

2. To stir about energetically; to strive to succeed; to bustle about. [Slang, Western U.S.]

3. To steal; -- used of livestock and esp. of cattle.

   To rustle up To gather or find by searching; as, to rustle up some food for supper.