founder (v.) Copy link Outline 1. perh. pessum eo, abeo2. submergo, si, sum, 3 (in pass.) • founder (v.): 1. perh. pessum eo, abeo: comp. Pl. Rud. 2, 3, 64. 2. submergo, si, sum, 3 (in pass.): v. to sink.