appoint 通常指不经过选择的官方委任。
designate 书面用语，侧重当权者或机构的选拔或任命，有时含强行指定的意味。
assign 常指给一群人或个人分配、分派、指派或委派任务。
name 普通用词，着重任命的结果，而不是过程。
nominate 通常指为某一公职选择候选人，并将其提交给有决定权的人作最后决定。
参考例句
1. He was nominated for the MP. 他被提名为议员候选人。
2. We cannot have a president or nominate (nominee) who represents the * style *(status quo). 我们不能有一个代表现状的总统或被提名人。
3. Could either of you ever nominate someone to the Supreme Court who disagrees with you on this issue? 你们两人之一曾提名与你在此问题上持不同意见的最高法院法官吗？
英英解释
v.
1. propose as a candidate for some honor
2. put forward; nominate for appointment to an office
3. charge with a function; charge to be
4. create and charge with a task or function
