laborer; construction worker; coolie
Refers to a manual laborer, especially in construction or heavy work. The gloss 'coolie' is dated and potentially offensive; modern usage is closer to 'laborer' or 'construction worker'. The word is potentially sensitive in modern use, likely because of the homophone 妊婦 (pregnant woman).
Many laborers are working at the site.
When he was young, he made a living as a laborer.