a person who has attained prajna, or Enlightenment, but who postpones Nirvana in order to help others to attain Enlightenment: individual Bodhisattvas are the subjects of devotion in certain sects and are often represented in painting and sculpture.
bo·dhi·satt·va (bō'dĭ-sŭt'və) n.
Buddhism An enlightened being who, out of compassion, forgoes nirvana in order to save others.
[Sanskrit bodhisattvaḥ, one whose essence is enlightenment : bodhiḥ, perfect knowledge; see bheudh- in Indo-European roots + sattvam, essence, being (from sat-, existing; see es- in Indo-European roots).]