the fact of being older or of a higher rank than others 年长；级别高◆a position of seniority 高级职位
the rank that you have in a company because of the length of time you have worked there 资历◆a lawyer with five years' seniority 拥有五年从业资历的律师◆Should promotion be based on merit or seniority? 晋升应该看业绩，还是看资历？