The KJV of pascha (to be translated instead as "the Passover") in Acts 12:4. "Easter" is a Christian feast; the Passover is a Jewish feast. (Pesach ("Feast of Passover".))
Bibliography Information Fausset, Andrew Robert M.A., D.D., "Definition for 'Easter' Fausset's Bible Dictionary". bible-history.com - Fausset's; 1878.