General synonyms:
* Rivalry
* Contention
* Striving
* Ambition
* Drive
* Aggressiveness
* Assertiveness
More specific synonyms:
* Zeal: implies intense enthusiasm and eagerness to succeed
* Enterprise: refers to a spirit of initiative and willingness to take risks
* Hustle: suggests a relentless and energetic pursuit of success
* Tenacity: emphasizes perseverance and determination
* Vigor: highlights energy and strength in the pursuit of competition
Antonyms:
* Cooperation
* Collaboration
* Compromise
* Indifference
* Passivity
The best word to use will depend on the specific meaning you want to convey.