arm up

arm up

To provide, accumulate, or take up weapons, as in preparation for war or fighting. All citizens must be prepared to arm up in the face of a foreign invasion. The king decided to arm up his soldiers in anticipation of an attack from the neighboring country.
See also: arm, up
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
See also:
References in classic literature ?
Mary Anne with her face to the window, held her arm up.
Reach right arm up high, inwardly rotating arm so that the palm of the hand faces backward.