Dictionary.com
definitions

Greek cross

noun
  1. a cross consisting of an upright crossed in the middle by a horizontal piece of the same length.

Origin of Greek cross

First recorded in 1715–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for greek cross

Greek cross

noun
  1. a cross with each of the four arms of the same length
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