Song of the once penniless lady (3)
I believe the answer is:
lay
'song' is the definition.
(poetic term for a song)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for lay that I've seen before include "Put down (in position)" , "Put down (eg, card)" , "Non-clerical, amateur" , "Set down; song" , "Not a religious" .)