Word 1) concession = compromise = something that you let someone have in order to end an arguement

Example sentence 1) The government refused to give any concessions to the powerful drug barons.

Example sentence 2) The firm will be forced to make concessions if it wants to avoid a strike.

Example sentence 3) Since I thought that this matter would not make any difference in our decision making , I made concession to him in  this part of arguement.

Word 2) corrupt = dishonest = using your power in a dishonest or illegal way in order to get an advantage for yourself

Example sentence 1) A grand jury accused the police department of being brutal and corrupt.

Example sentence 2) The whole system is inefficient and corrupt.

Example sentence 3) When one of my old friends in middle school became a high leveled governement official, he was very promising but in the long run, since he couldn't control of his power in a proper way, he went corrupt and failed his career in the field.

Word 3) populous = having many people = a populous area has a large population in relation to its size

Example sentence 1) China is the most populous country in the world.

Example sentence 2) Indonesia, with 216 million people, is the fourth most populous country in the world.

Example sentence 3) The country's most populous region was plagued by the worst floods ever recorded.