- full of, characterized by, or due to zeal; ardently active, devoted, or diligent.
Origin of zealous
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- filled with or inspired by intense enthusiasm or zeal; ardent; fervent
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for underzealous
1520s, from Medieval Latin zelosus (source of Italian zeloso, Spanish celoso), from zelus (see zeal). Related: Zealously, zealousness.
Online Etymology Dictionary, © 2010 Douglas Harper