A traitor.
compound interest
A person who is not a legal employee of the company but who works on specific asignments in the company's interest.
An economic interest group works to gain economic advantages for its members.
Adam Martindale has written: 'The country survey-book' 'The country-survey-book' -- subject(s): Early works to 1800, Mathematics, Interest, Surveying
When one person works for another under very menial and demanding conditions, against their will. It's the against their will bit which is really the defining issue.
That would be a lobbyist. Most of them have worked for--or are working--for companies that provide products or services for the government.
Buoyant force works against the force of pulling.
Funcionario is a person who works for Government of a country. A funcionario can be a secretary, policeman....but not a politician.
When politician works for the interest
In order to protect itself against other country's with their help. It works both ways in an alliance.
To me it means that the person who works against change is generally the person causing the problems the change is trying to fix.
A person who works for money is a Businessman or Businesswoman