conventĭcŭlum (noun N) : dim.conventus (rare).
* An assembly, meeting, association: conventicula hominum, quae postea civitates nominatae sunt, Cic. Sest. 42, 91: plebei urbanae,id. Dom. 28, 74.
* A place of assembly, Tac. A. 14, 15: ritus Christiani,Amm. 15, 5, 31; 27, 3, 13; Arn. 4, 152; Lact. 5, 11, 10.

s. TLL