adj.多余的，无用的

The presence of a security system that never triggers is otiose.
安装了从未启动过的安全系统是无用的。
A backup plan that you never use is as otiose as not having one at all.
一个从未使用过的备份计划和根本没有一样无用。
The committee's discussions were purely otiose, leading to no tangible outcomes.
委员会的讨论完全是徒劳的，没有产生任何实质性结果。
In the context of modern warfare, cavalry charges have become otiose.
在现代战争的背景下，骑兵冲锋已经变得无用。
A law that is never enforced is otiose and undermines the credibility of the legal system.
一条从未执行的法律是无用的，并且削弱了法律体系的信誉。
An otiose meeting is a waste of everyone's time and resources.
一场无效的会议是对所有人时间和资源的浪费。
A redundant feature in a smartphone can be considered otiose.
智能手机中多余的功能可以被认为是无用的。
A dictionary with definitions already known to the reader is otiose.
对读者来说，字典中的定义都是已知的，那么这本字典就是无用的。
The existence of an extra key for a lock that has been replaced is otiose.
换了锁之后，原有的钥匙就变得无用了。
A training program that does not enhance skills or knowledge is otiose.
不能提升技能或知识的培训计划是无用的。