Former nobleman -- one with the Queen (7)
I believe the answer is:
earlier
'former' is the definition.
(thesaurus)
'nobleman one with the queen' is the wordplay.
'nobleman' becomes 'earl' (earl is a kind of nobleman).
'one' becomes 'i' (Roman numeral).
'with' says to put letters next to each other.
'the queen' becomes 'er' (Elizabeth Regina).
'earl'+'i'+'er'='EARLIER'
(Other definitions for earlier that I've seen before include "Further back in time" , "Prior" , "of a bygone age?" , "Sooner in time" , "Formerly" .)