CC Ādi 4.99-100
rādhā-bhāva-kānti dui aṅgīkāra kari’
ei ta’ pañcama ślokera artha paracāra
prema-bhakti — devotional service in love of Godhead; śikhāite — to teach; āpane — Himself; avatari — descending; rādhā-bhāva — the mood of Śrīmatī Rādhārāṇī; kānti — and luster; dui — two; aṅgīkāra kari’ — accepting; śrī-kṛṣṇa-caitanya — of Lord Caitanya Mahāprabhu; rūpe — in the form; kaila — made; avatāra — incarnation; ei — this; ta’ — certainly; pañcama — fifth; ślokera — of the verse; artha — meaning; paracāra — proclamation.
To promulgate prema-bhakti [devotional service in love of Godhead], Kṛṣṇa appeared as Śrī Kṛṣṇa Caitanya with the mood and complexion of Śrī Rādhā. Thus I have explained the meaning of the fifth verse.