What is the Latin word for president?

Rome had an emperor and a senate. The emperor was "Imperator" or simply "Caesar" to indicate the revered implied bloodline. The senate was "senatus." The ruling body was considered twofold during the republic, as indicated by the Roman Standard of battle, "SPQR." This was "SENATVS ET POPULUSQUE ROMANVS", or "the senate and the people of rome."