dispensable
/dɪˈspensəbl/adjective
1- able to be replaced or done without; superfluous可替代的; 可有可无的; 多余的：
the captain's loss of form made him dispensable.
船长失落的状态使他成了累赘。
1.1
- (of a law or other rule) able to be relaxed in special cases（法律或其他规则）在特定情况下可放宽的, 可通融的。
派生词
dispensability
noun词源
early 16th cent. （in the sense 'permissible in special circumstances'）： from medieval Latin dispensabilis, from Latin dispensare （see DISPENSE）.