Noblewoman welcoming fifty? More indeed! (9)
I believe the answer is:
countless
'more indeed' is the definition.
I can't tell whether this definition defines the answer.
'noblewoman welcoming fifty?' is the wordplay.
'noblewoman' becomes 'countess' (countess is a kind of noblewoman).
'welcoming' indicates putting letters inside (in sense of 'inviting in').
'fifty?' becomes 'L' (Roman numeral).
'countess' enclosing 'l' is 'COUNTLESS'.
Can you help me to learn more?
(Other definitions for countless that I've seen before include "Very many" , "Innumerable" , "Legion seeming to be" , "not so important" , "Untold" .)