Marian has a song in her heart (4)
I believe the answer is:
aria
'a song in her heart' is the definition.
I can't tell whether this definition defines the answer.
'marian has' is the wordplay.
'has' says the answer is hidden in the clue.
'ARIA' is hidden within 'marian'.
Can you help me to learn more?
(Other definitions for aria that I've seen before include "Operatic solo, duet, etc" , "Song for solo voice from an oratorio, cantata etc" , "Summertime perhaps" , "Puccini item" , "Piece of music" .)