Openings of three roads use a lot of labour (7)
I believe the answer is:
travail
'labour' is the definition.
(I know that labour can be written as travail)
'openings of three roads use' is the wordplay.
'openings of' says to take the initial letters (I've seen 'opening' mean this).
'use' becomes 'avail' (availing is a kind of using).
The initial letters of 'three roads' is 'tr'.
'tr'+'avail'='TRAVAIL'
'a lot of' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for travail that I've seen before include "Labour, toil" , "Hard work" , "Painful or laborious effort, like childbirth" , "In old use, the pains of childbirth" , "Use of physical or mental energy; excessive labour..." .)