Support lord audibly (4)
I believe the answer is:
pier
'support' is the definition.
(pier is a kind of support)
'lord audibly' is the wordplay.
'lord' becomes 'peer' (peer is a kind of lord).
'audibly' shows a homophone (sound like).
'peer' sounds like 'PIER'.
(Other definitions for pier that I've seen before include "Coastal platform" , "Supporting structure" , "Landing stage; arch support" , "Part of airport terminal; breakwater" , "Break-water or landing stage" .)