(in the US) a preliminary election to appoint delegates to a party conference or to select the candidates for a principal, especially presidential, election

these two Republicans should win their primaries easily

a primary colour

the Palaeozoic era

(in the US) run against (the current holder of a political office) in the preliminary election a party uses to select its candidate for the main election

I'm not primarying the president, and no one else should either unless we want to lose the White House