cursus

Cursus, cursus is masculine, fourth declension, from curro, "I run". Fourth declension means the genitive singular, the nominative plural and the accusative plural all read cursus, and only the sentence tells you which; the dative and ablative plural is cursibus.

Two set phrases are worth carrying. The cursus honorum is the fixed ladder of Roman public offices, quaestor to aedile to praetor to consul, with minimum ages attached, and a career described as running it is being praised for doing things in order. The cursus publicus is the imperial courier service, relay horses and staging posts, effectively the state post. English course, cursor, cursive and concourse all descend from the same verb.