What does archangel mean?
The definition of archangel
Arch`an”gel, n.
Etym: [L. archangelus, Gr. archangel, F. archange. See Arch-, pref., and Angel.]

1 A chief angel; one high in the celestial hierarchy. Milton.
2 (Bot.)
A term applied to several different species of plants (Angelica archangelica, Lamium album, etc.).