Lewis & Short

pistor, ōris, m. [pinso; root in Sanscr. pish-, to crush; cf. Gr. πτίσσω], one who pounds corn in a mortar or grinds it in a hand-mill, a miller (only so in Plaut.).

  1. I. Lit.: nec pistorem ullum nossent, nisi eum, qui in pistrino pinseret farinam (far?), Varr. ap. Non. 152, 14; cf. id. ib. 16: pistores tantum eos qui far pinserunt nominatos, At. Cap. ap. Plin. 18, 11, 28, § 107; Plaut. Capt. 4, 2, 27; id. Trin. 2, 4, 6; Gell. 3, 3, 14.
  2. II. Transf., a baker (class.): pistores Romae non fuere ad Persicum usque bellum … ipsi panem faciebant Quirites, mulierum id opus erat, Plin. 18, 11, 28, § 107: ut tuus pistor bonum faceret panem, etc., Varr. ap. Gell. 15, 19, 2; Suet. Caes. 48: mitto hasce artes vulgares, coquos, pistores, lecticarios, Cic. Rosc. Am. 46, 134; id. Fin. 2, 8, 23; id. Arch. 46, 134; Sen. Ep. 15, 3, 24; Vulg. Gen. 40, 1. At Rome the bakers formed a separate guild, Inscr. Don. cl. 9, n. 11; Inscr. Grut. 81, 10; 255, 1; Dig. 3, 4, 1; 27, 1, 46.
    1. B. A surname of Jupiter, because, when the Romans were besieged in the Capitol, he gave them the idea of hurling bread, as though they had an abundance of it, at the besieging Gauls, Ov. F. 6, 350; 394; Lact. 1, 20.
    2. C. Pastry-cooks were also called pistores, Mart. 11, 31, 8; 14, 222; Petr. 60.