Webster's Revised Unabridged Dictionary · 1913

Zealous

Zealous (?; 277) , adjective

[Late Latin zelosus. See Zeal.]

1.
Filled with, or characterized by, zeal; warmly engaged, or ardent, in behalf of an object.
He may be zealous in the salvation of souls. — Law
2.
Filled with religious zeal. [Obsolete] — Shakespeare