Former title held by the daughter of a Portuguese king (7)
I believe the answer is:
infanta
'king' is the definition.
(I know this)
'former title held by the daughter of a portuguese' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
'a' could be 'an' and 'an' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for infanta that I've seen before include "girl in foreign court" , "foreign title" , "Royal personage" , "King of Spain's daughter" , "Spanish princess" .)