challenger

the primary or most important opponent

a powerful opponent

an opponent who has a real chance of winning

the opponent who is nearest in position or score

the opponent who is closest in position or score

an opponent who inspires fear or respect through being impressively powerful

a candidate challenging the incumbent for the presidency

an opponent who deserves respect or consideration

a challenger from the Conservative party

a challenger from the Democratic party

a challenger from the Labour party

a challenger from the Republican party

to win against an opponent in a competition

to defeat an opponent in a competition

to confront or compete against an opponent

to accept a challenge and compete against an opponent

indicates the title or position being competed for

indicates the person or entity being challenged