Lady once thrilled to host working author (5,5)
I believe the answer is:
conan doyle
'author' is the definition.
(I have seen 'popular author' mean 'conan doyle' so perhaps 'author' could also mean 'conan doyle')
'lady once thrilled to host working' is the wordplay.
'thrilled' indicates an anagram (letters get excited or thrilled).
'to host' indicates putting letters inside (inserted letters are hosted or welcomed).
'working' becomes 'on' (e.g. a machine is working or on).
'lady'+'once'='ladyonce'
'ladyonce' anagrammed gives 'candoyle'.
'candoyle' placed around 'on' is 'CONAN DOYLE'.
(Other definitions for conan doyle that I've seen before include "A Study in Scarlet author" , "popular author" , "mystery writer" , "The Lost World author" , "Holmes creator" .)