Royal daughter hosting a president (6)
I believe the answer is:
reagan
'president' is the definition.
(Ronald Reagan)
'royal daughter hosting a' is the wordplay.
'royal' becomes 'r' (abbreviation).
'daughter' becomes 'egan' (I can't justify this - if you can you should give a lot more credence to this answer).
'hosting' indicates putting letters inside (inserted letters are welcomed in or hosted).
'egan' enclosing 'a' is 'eagan'.
'r'+'eagan'='REAGAN'
Can you help me to learn more?
(Other definitions for reagan that I've seen before include "US president, 1981-89" , "head of state" , "40th president of the United States" , "leading actor, once?" , "Ronald . . . . . ., a film star and president" .)