Heavy burdens are a common theme in literature and life, often referring to the struggles and hardships that one must bear. WOES, onuses, and MILLSTONES are all words used to describe heavy burdens. WOES are deep sorrows or troubles, onuses are obligations or responsibilities, and MILLSTONES are figurative weights that can be difficult to carry. Together, these three words represent the idea of heavy burdens that can be difficult to manage.