The process of passing through a membrane, pore or interstice(noun)
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Use "transudation" in a sentence
"Onopordinis_, but proportionably more elongate and less convex; rostrum and thorax longer; pilosity of the body underneath much thinner and shorter; thighs thicker, more clavate, the anterior evidently costate-rugose underneath; without whitish marks on the elytra, and without that layer of light-brown earth-like pollinose transudation which is often wanting in rubbed specimens of _Larinus"
"If we do not dilute it sufficiently, it is diluted in the stomach by transudation of water in the stomach, until the required reduction for its absorption; the current then sets in toward the blood, and passes into the circulating canals by the veins."
"Some of the air which enters the lung gets from the bronchial tubes into the blood-vessels by transudation, for there is no direct communication between them; and this air, penetrating the body, rapidly cools the blood throughout the vessels."