"Armed cap-a-pie" is an unusual and obscure phrase that means someone is dressed in full armor or fully equipped for battle. There are several other phrases and idioms that can be used to convey a similar idea, such as "suited up," "fully armed," "battle-ready," or "armed to the teeth." All these expressions describe someone who is entirely prepared to engage in conflict or face danger. "Armed and dangerous" is another popular phrase that encompasses the same meaning. Whatever the phrasing might be, it is crucial to note it as an effective means of communication to express the idea of being fully prepared for any eventualities that might arise.