Very many noblemen welcoming the French (9)
I believe the answer is:
countless
'very many' is the definition.
(I've seen this before)
'noblemen welcoming the french' is the wordplay.
'noblemen' becomes 'counts' (count is a kind of nobleman).
'welcoming' is an insertion indicator (in sense of 'inviting in').
'the french' becomes 'les' ('the' in French).
'counts' placed around 'les' is 'COUNTLESS'.
(Other definitions for countless that I've seen before include "Very many" , "Innumerable" , "not so important" , "enormous number" , "Untold" .)