Aiden/Aidan is just beginning to wander into the girls' side of the gender divide, but with so many little boys given the trendy Aiden name today -- it's number one in some states -- we don't recommend it for girls.

Aiden in all its spelling variations is the anglicized version of the Irish Aodhán, which was originally a pet form of the Irish name Aodh (pronounced 'ee'), who was the old Celtic god of the sun and fire. St. Aidan was a famous seventh century Irish saint, noted for his kindness and generosity and for spreading Christianity.