Marching Orders Meaning

(idiomatic) Dismissal: an instruction to leave.

Example: Instructions for action.
  I get my marching orders directly from the president.
2011 October 20, Michael da Silva, “Stoke 3 - 0 Macc Tel-Aviv”[1], BBC Sport:
  Riled by a decision that went against him, Ziv kicked his displaced boot at the assistant referee and, after a short consultation between the officials, he was given his marching orders and the loudest cheer of the night.