Liath Luachra or the "Grey one of Luachair", is the name of two characters in the Fenian Cycle of Irish mythology.
[1] The first Liath Luachra is one of Fionn's foster mothers who raise him after the death of his father Cumhal at the hands of Goll mac Morna.
She is a great warrior and a companion of Fionn's aunt, the druidess Bodhmall; together they raise the boy in secret in the forest of Sliabh Bladhma.
Eventually Fionn's ever-spreading fame threatens to bring his father's killers to him, and his caretakers send him to find his own way.
Eventually he kills a young warrior named Glonda; Fionn sees the man's mother crying blood over the murder and decides to avenge him.