manual, physical
back-breaking, forced, hard
He was sentenced to four years hard labour for his crime.

productive, unproductive
unpaid

withdraw
The miners are threatening to withdraw their labour.

productivity
camp
Dissidents were forced to work in labour camps.

free, organized
wage
cheap, low-cost
casual, day (AmE)
skilled, unskilled
illegal
foreign, immigrant, migrant
child, slave
It is now thought that the Pyramids were not built using slave labour.

prison
farm
sweatshop

force
the size of the labour force

market, pool, supply
an increasingly competitive labour market

shortage
cost, costs
movement
tensions between the labour movement and government

organization
activist, leader
relations
dispute
law

difficult, easy
long, short
The baby was born after a long labour.

preterm
women at risk of preterm labour

go into
She went into labour two weeks early.

induce
Labour was induced when the baby was ten days overdue.

room, ward (BrE)
pains

in labour
She was in labour for ten hours.