As a Noun:
1. A situation in which two or more people, groups, organisations or businesses are trying to get something which not everyone can have. English = competition, rivalry.
2. Someone you are competing with. English = competitor, rival.
3. In a game or competition, the person who is playing against you; in politics, the political group or party that is not part of the government. English = opponent, opposition; opposition.
4. An illness that you have when you eat, smell, or touch a substance which does not normally make people ill. English = allergy.
As a Verb or Adjective:
1. To try and get something for yourself in a situation where other people are also trying to get it. English = compete.
2. Of businesses and firms, to try to get people to buy its own goods or services. English = compete.
3. To disagree with what someone wants to do and to try to prevent them form doing it. English = oppose, (be) opposed to.
4. To become ill when you eat, smell, or touch a substance which does not normally make other people ill. English = (be) allergic.