Je was op zoek naar: emissarium (Latijn - Engels)

emissarium
emissarium, emissari(i) channel for surplus water, drain; outlet for morbid matter (medical); emissarium, emissarii exhaust pipe;

ille vero qui dimiserit caprum emissarium lavabit vestimenta sua et corpus aqua et sic ingredietur in castr
and he that let go the goat for the scapegoat shall wash his clothes, and bathe his flesh in water, and afterward come into the camp.