After securing that high-paying job, she and her family became quite well-off and moved to a better neighborhood.

well 在这里是副词，表示"很好地、充分地"，用于修饰形容词或副词。 off 本义是"离开、脱离"，在复合词中常表示"状态"或"情况"。 well-off 是固定搭配，表示"经济状况良好的、富裕的"，形容一个人或家庭拥有足够的财富和资源。