Birthday - Vine's Expository Dictionary of New Testament Words
Birthday[ 1,,G1077, genesia ]
a neuter plural (akin to genesis, lineage," from ginomai), primarily denoted "the festivities of a birthday, a birthday feast," though among the Greeks it was also used of a festival in commemoration of a deceased friend. It is found in Matthew 14:6; Mark 6:21. Some have regarded it as the day of the king's accession, but this meaning is not confirmed in Greek writings.