Floor or platform for speaker (5)
I believe the answer is:
stump
'floor' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stump that I've seen before include "Tree remnant; baffle" , "Component of wicket" , "Cricket stick" , "defeat" , "Remains of tree - puzzle" .)