If you refer to someone as an overlord, you mean that they have great power and are likely to use it in a bad way.
例句
We really don't want to be the overlords of the Palestinian population...我们真的并不希望成为巴勒斯坦人民的太上皇。The running of Welsh rugby was left in chaos yesterday after a vote of no confidence in the game's overlords.昨天，在对威尔士橄榄球界几位巨头投了不信任票后，该运动的管理陷入一片混乱。
N-COUNT
（旧时的）君主，领主
In former times, an overlord was someone who had power over many people.
例句
Henry II was the first king to be recognized as overlord of Ireland.亨利二世是第一位被承认为爱尔兰领主的国王。
英汉词典释义
n.
最高领主;霸主
We cadres are ordinary workers and not overlords sitting on the backs of the people.我们干部是普通劳动者,不是骑在人民头上的老爷。We must not catch the bad habit of “acting as overlords”.我们不应该染上“当官做老爷”的坏习气。