Princess visiting Trinidad (3)
I believe the answer is:
ida
'princess' is the definition.
(Princess Ida is a Gilbert and Sullivan opera)
'visiting trinidad' is the wordplay.
'visiting' indicates the answer is hidden within the clue (the answer 'visits' the inside of the clue).
'IDA' can be found hidden inside 'trinidad'.
(Other definitions for ida that I've seen before include "Poetic princess" , "noted princess" , "Mountain in Crete" , "Greek mount - Gilbertian princess" , "Cretan mount" .)