1. a principal rival; a competitor or opponent against whom one has a long-standing, intense rivalry
Usage: often used in sports, business, or personal contexts; typically singular but can be used in plural

Examples

• The two basketball teams have been archenemies for decades, with each season's matchup against their archrival drawing massive crowds.
• Apple and Microsoft were archenemies in the personal computer market throughout the 1990s.
• In the novel, the protagonist finally confronts her archrival in a dramatic showdown.
• The company's archrival just launched a competing product that threatens their market share.
• High school sports rivalries often pit students against their archenemies from neighboring towns.
• He considered his former business partner his archrival after their bitter split.
• The two chess champions were archenemies, each determined to defeat the other in their next match.