Support aristocrat when speaking (4)
I believe the answer is:
pier
'support' is the definition.
(I know that pier is a type of support)
'aristocrat when speaking' is the wordplay.
'aristocrat' becomes 'peer' (peer is a kind of aristocrat).
'when speaking' indicates a 'sounds like' (homophone) clue.
'peer' is a homophone of 'PIER'.
(Other definitions for pier that I've seen before include "Landing-stage or promenade" , "Seaside resort feature" , "Ripe as a jetty (4)" , "Part of airport terminal; breakwater" , "Breakwater; arch pillar" .)