(Military) (esp formerly) a bugle note used as an order to a military force to attack
[C13: from Old Northern French, from warir to protect, of Germanic origin; compare Old English warian to defend]
war•i•son(ˈwær ə sən)
a bugle call to assault.
[1805; Walter Scott's misinterpretation of now obsolete waryson reward, wealth, Middle English < Anglo-French warison defense, possessions, Old French garison; see garrison]