Definition of birthday

• n. - The day in which any person is born; day of origin or commencement.
• n. - The day of the month in which a person was born, in whatever succeeding year it may recur; the anniversary of one's birth.
• a. - Of or pertaining to the day of birth, or its anniversary; as, birthday gifts or festivities.
• n. - The day in which any person is born; day of origin or commencement.
• n. - The day of the month in which a person was born, in whatever succeeding year it may recur; the anniversary of one's birth.
• a. - Of or pertaining to the day of birth, or its anniversary; as, birthday gifts or festivities.