in Buddhism, a being that has attained perfect enlightenment but compassionately refrains from entering nirvana in order to save others
Traditionally read as ‘one who aspires to enlightenment’, a bodhisattva is someone who has set out on a path of many lifetimes in order to become a buddha and liberate all beings from suffering. The bodhisattva doctrine is important in all forms of Buddhism, but receives special emphasis in the Mahayana, where the bodhisattva becomes a figure for both emulation and devotion — Professor Donald Lopez
[Sanskrit bodhisattva a being whose essence is enlightenment, from bodhi enlightenment + sattva being]