rival
n. countablen. a person or group that is competing with you for the same thing. You use this for someone who is trying to win the same prize, job, or goal.
n. a person or entity competing with another for the same objective or for superiority in the same field.
The two companies are rivals in the smartphone market.
The local team beat their biggest rival in the final game of the season.
Despite being fierce rivals for the promotion, the two colleagues maintained a professional relationship and collaborated effectively on the final project.
Learned borrowing from Latin rīvālis (literally “person using the same stream as another”).
Often followed by the preposition 'for' (rivals for the title) or 'in' (rivals in business).
They are rivals of each otherThey are rivalsWhile 'rival of' is grammatically possible, 'rivals' is inherently reciprocal; adding 'of each other' is redundant.