1. A class of men employed about docks, taking goods from barges and flats.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• heaverly,
• hearlers,
• heves,
• huvers,
• heavean,
• heavery,
• hevens,
• heavyer,
• nervers,
• behavers,
• heavans,
• hever,
• heavry,
• heaiver,
• heavns,
• heavys,
• feavers,
• hefers,
• peaves,
• theaves

• haverstock,
• haversack.

The adjective form of "heavers" would be "heaving".