SB 5.7.3

ajanābhaṁ nāmaitad varṣaṁ bhāratam iti yata ārabhya vyapadiśanti.
Word for word: 
ajanābham — Ajanābha; nāma — by the name; etat — this; varṣam — island; bhāratam — Bhārata; iti — thus; yataḥ — from whom; ārabhya — beginning; vyapadiśanti — they celebrate.
Translation: 
Formerly this planet was known as Ajanābha-varṣa, but since Mahārāja Bharata’s reign it has become known as Bhārata-varṣa.
Purport: 

This planet was formerly known as Ajanābha because of the reign of King Nābhi. After Bharata Mahārāja ruled the planet, it became celebrated as Bhārata-varṣa.