Definition, synonyms and related words
plural of rival
"The two football clubs are fierce rivals in the league, always competing fiercely for the championship title."
Third-person singular simple present indicative form of rival
"The team captain rivals his coach in stubbornness during every practice session."
In plain English: To rival someone means to try as hard as you can to beat them at something they are good at.
"The two companies are rivals for market share in this region."