Trees , we hear, that will cover billiard table (5)
I believe the answer is:
baize
'will cover billiard table' is the definition.
I can't tell whether this definition defines the answer.
'trees we hear' is the wordplay.
'trees' becomes 'bays' (bay is a type of tree).
'we hear' shows a homophone (sound like).
'bays' sounds like 'BAIZE'.
'that' is the link.
Can you help me to learn more?
(Other definitions for baize that I've seen before include "Felt-like material" , "Green felt" , "table-topper" , "Green stuff" , "On which one skis" .)