IPA: /ʌnˈlɪmbər/
KK: /ʌnˈlɪmbər/
To get ready for action or to prepare equipment for use.
The soldiers began to unlimber their artillery before the battle.
Past: unlimbered
Past Participle: unlimbered
To prepare or set something up for use, especially by detaching it from a support or transport.
The soldiers worked quickly to unlimber the artillery before the battle began.
Past: unlimbered
Past Participle: unlimbered
Unlimber → It is formed from "un-" (meaning not) and "limber" (from Middle English "limber", meaning flexible or pliable). The word "unlimber" means to make something not flexible or to remove the constraints that limit movement.
Think of making something 'not flexible' ('un-') — that's why unlimber means to free something from its constraints.