In Jewish, Christian, and Muslim teaching, an archangel is one of the most important angels — a chief messenger, not an ordinary one. The names Christian talk knows best are Michael, Gabriel, and Raphael, though different churches list them a little differently. Though actually, not every faith draws the rank the same way: some writers treat “archangel” as a small, named group, others as a high order of angels. In everyday English the word is mostly religious or literary; you will also see it as a church name or, loosely, for a powerful protector. It has nothing to do with archaeology. The arch- here means “chief,” the same idea as in archbishop, not “ancient.”