Lewis & Short

postĭlĭo, ōnis, f. [postulo; cf. consilium from consulo]. Relig. t. t., a claim of a god upon men, a demand for the fulfilment of a forgotten sacrifice (cf. postulatio, with which it is confounded in many MSS. and edd.; mostly ante- and post-class.): de re scriptum est, postiliones esse Jovi, Saturno, Neptuno, Telluri, dis caelestibus, Cic. Har. Resp. 10, 20: eodem ostento Telluri postilio deberi dicitur, id. ib. 14, 31: deum Manium postilionem postulare, Varr. L. L. 5, § 148 Müll.: in caeremoniis vestris postulionibus locus est, Arn. 4, 148.