Knight Up

From SuspireWiki

(v., slang)

To arm oneself, dress impressively and prepare to intimidate, posture impressively and possibly do violence, especially in service to one’s lord; to summon one’s courage and poise. This is a low-class expression calling the listener to prepare for a more highclass kind of violence (or the threat thereof). “As long as they think we weak, they ain’t going to stop coming here, so shut up, knight up and let’s show them we’re not boys.”