a person who makes a bid

person with whom one competes

opposite to something

antagonistic; opposite

a person who actively disagrees

disagreeing, differing

not agreeing; harsh in (musical) tone

different, conflicting

a person engaged in a lawsuit

person with whom one competes

expressing 'no', 'not', a refusal; lacking commitment, enthusiasm; (of number or amount) less than zero

bad, contradictory

a person against whom one fights, struggles, plays games, contests an election or argues

person with whom one competes