BT BM 86a(47) :אתרא דנהיגי למכרך ריפתא ומישתא אנפקא ומיזל לדברא‏ : a place where they customarily eat a meal, drink unmixed wine, and go to the field
See the entire entry for ˀăṯar, ˀaṯrā n.m. place