1. Roman law. A purchaser of something at a state auction, esp. a right or advantage, as in the right to farm taxes. See CONDUCTOR(2).
“Manceps. One who at a public auction, conducted by a magistrate, through the highest bid obtained the right to collect taxes (a tax farmer) or custom duties, the lease of public land (ager publicus) or other advantages (a monopoly). — In postal organization manceps was a post-station master.” Adolf Berger, Encyclopedic Dictionary of Roman Law 573 (1953).
2. A person who undertakes to perform a task and gives security for the performance.
3. Roman law. A state postmaster.