used when a person, thing, or group of people seems to have been rented for a particular purpose and is not sincere

Most of the people on the protest seemed to be rent-a-mob, not real supporters. 大多数抗议者好像是花钱雇来的乌合之众，并不是真正支持抗议活动的。

humorous Old rent-a-quote is always turning up on TV to give his opinions. 那个拾人牙慧的老家伙总是上电视发表他的观点。