Lewis & Short

congestīcĭus or -tĭus, a, um, adj. [1. congero], brought together, heaped or piled up (rare; mostly post-Aug.): agger ex materiā, Caes. B. C. 2, 15; cf. materia, Col. 2, 16, 5: humus, id. 2, 10, 18: terra, Pall. Sept. 7; id. Oct. 11, 2: congesticius aut paluster locus, Vitr. 3, 4, 2.