from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun The Monday following Easter, observed as a holiday in some countries.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- proper noun The Monday after
Easter Sunday; a bank holidayin Britainand a holidayin many other places.
Sorry, no etymologies found.
But when Easter Monday and his birthday arrived together, without bringing any birthday remembrance other than a letter from his old chum, Charlie Henchman, Reggie's heart went down to a depth for which he had no idea there was room in his mechanism.