There are multiple definitions - click on the translation that matches your context.

hard labour means:

trabalhos forçados

substantivo plural

full

hard labour

noun

This type of punishment is not allowed under the Brazilian Constitution (Article 5, XLVII, c).

the punishment of sending someone to a prison or other place to do physically tiring manual work, such as breaking rocks or building walls etc

I sentence the accused to 24 months imprisonment with hard labour.