Hold forth; speak (5)
I believe the answer is:
orate
I believe this is a double definition.
'hold forth' is the first definition.
(I've seen this in another clue)
'speak' is the second definition.
(orating is a kind of speaking)
(Other definitions for orate that I've seen before include "Erato (anag.)" , "Talk pompously" , "Make a lengthy speech" , "Pontificate" , "Spout" .)