Rasarnavasudhakara 3.451

3.451

atha geya-padam-
vīṇādi-vādanenaiva sahitaṃ yatra bhāvyate |
lalitaṃ nāyikā-gītaṃ tad geya-padam ucyate ||

Now, geyapada:
Where graceful singing by the heroine, accompanied merely / by the playing of the lute and other instruments, is performed, that is called geyapada.