CONTENDING

Maintain or assert

Example: "He contended that communism had no future"

Have an argument about something

To make the subject of dispute, contention, or litigation

Example: "They contested the outcome of the race"

Succeed in doing, achieving, or producing (something) with the limited or inadequate means available

Example: "We got by on just a gallon of gas"

Compete for something; engage in a contest; measure oneself against others

Be engaged in a fight; carry on a fight

Example: "The tribesmen fought each other"