also: ライヴァル
A person, group, or entity that competes with another for the same objective or in the same field. Commonly used in sports, business, and personal contexts.
He is my biggest rival.
Those two companies have been rivals for many years.
He views his colleague Tanaka, who joined the company at the same time, as a rival.
I beat my long-time rival in the final match.
She has a strong sense of rivalry toward her younger sister.
ライバル emphasizes competition between people or companies, while 同業者 simply identifies someone in the same line of business without implying rivalry.