Old magistrate about to meet First Lady
I believe the answer is:
reeve
'old magistrate' is the definition.
(historical type of magistrate or judge)
'about to meet first lady' is the wordplay.
'about' becomes 're' (regarding).
'to meet' says to put letters next to each other.
'first lady' becomes 'eve' (first woman in the Bible).
're'+'eve'='REEVE'
(Other definitions for reeve that I've seen before include "local official" , "Old official in Bruree, venerated" , "Historical magistrate" , "Mediaeval officer; ruff's mate" , "Anglo-Saxon magistrate - female bird - pass (a rope) through a hole" .)