Definition.com
Agape is purely spontaneous, unmotivated, groundless, and creative. It is the love of God operating in the human heart.
Definition.com
Agape is disinterested love in which the individual seeks not his own good but the good of his neighbor.
Definition.com
Agape is love risen to a level where you begin to love men, not because they are likeable, but because God loves them.
Definition.com
Agape is recognition of the fact that all life is interrelated. All humanity is involved in a single process, and all men are brothers. To the degree that I harm my brother, no matter what he is doing to me, to that extent I am harming myself.