A note of consolation (3)
I believe the answer is:
sol
'a note' is the definition.
(musical note as in do-re-mi-fa-sol-la-ti)
'of consolation' is the wordplay.
'of' indicates a hidden word.
'SOL' is hidden within 'consolation'.
(Other definitions for sol that I've seen before include "The sun in 12 Across" , "Personification of the sun" , "Note, old french coin" , "Spanish and poetic sun" , "Note; Peruvian currency" .)