Bodhisattva
The word Bodhisattva is derived from Bodhi and Sattva, the former term meaning enlightened, and the latter term meaning sentimental. Strictly speaking, a Bodhisattva should be an enlightened being, such as Arhat or even Buddha, who regards the deliverance of sentient beings as the highest aspiration.
By definition, a true arhat eradicates the Three Poisons (greed, hatred and illusion) in the Three Realms (Desire, Form, Formlessness), then enters Nirvana.