SB 12.4.34

yadaivam etena viveka-hetinā
 māyā-mayāhaṅkaraṇātma-bandhanam
chittvācyutātmānubhavo ’vatiṣṭhate
 tam āhur ātyantikam aṅga samplavam
Synonyms: 
yadā — when; evam — in this way; etena — by this; viveka — of discrimination; hetinā — sword; māyā-maya — illusory; ahaṅkaraṇa — false ego; ātma — of the soul; bandhanam — the cause of bondage; chittvā — cutting off; acyuta — of the infallible; ātma — Supreme Soul; anubhavaḥ — realization; avatiṣṭhate — develops firmly; tam — that; āhuḥ — they call; ātyantikam — ultimate; aṅga — my dear King; samplavam — annihilation.
Translation: 
My dear Parīkṣit, when the illusory false ego that binds the soul has been cut off with the sword of discriminating knowledge and one has developed realization of Lord Acyuta, the Supreme Soul, this is called the ātyantika, or ultimate, annihilation of material existence.