Joiner employed in building industry (6)
I believe the answer is:
cement
'joiner' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for cement that I've seen before include "joiner" , "Material used by builders and dentists" , "It hardens when mixed with water" , "Bind firmly" , "Firmly fix" .)