anuttarā samyak-saṃbodhi[anuttarā sammā saṃbodhi] unexcelled perfect enlightenment. A samyak saṃbuddha is one who through his own efforts and wisdom understands dharma, and out of compassion proclaims it to the world in order to uplift others from saṃsāra and to lead them to liberation. The samyak-saṃbodhi is the state pertaining to a samyak-saṃbuddha. The samyak saṃbuddha makes others understand āryasatyāni, namely, suffering, cause of suffering, cessation of suffering and, way to cessation of suffering as he has known them. The śrāvaka-s and the pratyekabuddha-s attain enlightenment respectively known as śrāvakabodhi and pratyekabodhi. Śrāvakabodhi, pratyekabodhi and samyaksaṃbodhi are the three modes of enlightenment. The Bodhisattva-s opt for the anuttarā samyaksaṃbodhi which does not have anything further and beyond it.

     In his first discourse the Buddha has marked the characteristic of the anuttarā samyak saṃbodhi. He says, "I acknowledged that I had attained the incomparable supreme enlightenment only when the absolute true intuitive knowledge regarding truths became clear to me."

Buddhānusmṛti - A Glossary of Buddhist Terms

Dīgha Nikāya. Mahāparinibbāna, Pāsādika.