His part-time job could barely sustain him, let alone a family.

sustain 是动词，意思是"维持、支撑"，指提供必要的支持或资源使某事物能够持续存在或运作。这个词来自拉丁语 sustinere（支撑、承受），由 sub-（在下面）和 tenere（握住）组成，字面意思是"在下面支撑着"。