Eas·ter (??st?r)n.1. A Christian feast commemorating the Resurrection of Jesus.2. The day on which this feast is observed, the first Sunday following the full moon that occurs on or next after March 21.3. Eastertide.[Middle English ester, from Old English ?astre; see aus- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.Easter (?i?st?) n1. (Ecclesiastical Terms) the most important festival of the Christian Church, commemorating the Resurrection of Christ: falls on the Sunday following the first full moon after the vernal equinox2. (Ecclesiastical Terms) Also called: Easter Sunday or Easter Day the day on which this festival is celebrated3. the period between Good Friday and Easter Monday[Old English ?astre, after a Germanic goddess Eostre; related to Old High German ?star?n Easter, Old Norse austr to the east, Old Slavonic ustru like summer]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Eas?ter (?i st?r) n. 1. an annual Christian feast in commemoration of the resurrection of Jesus Christ, observed on the first Sunday after the first full moon after the vernal equinox. 2. Eastertide. [before 900; Middle English ester, Old English ?astre] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.EasterA feast commemorating the death and resurrection of Jesus.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited