n. A thin vesicle on the skin, containing watery matter or serum, whether occasioned by a burn or other injury, by a vesicatory, or by disease; a pustule.n. An elevation made by the lifting up of an external film or skin by confined air or fluid, as on plants, or by the swelling of the substance at the surface, as on steel.n. Something applied to the skin to raise a blister, as a plaster of Spanish flies, mustard, etc., as a means of counter-irritation; a vesicatory.n. In castings of different materials, an effect caused by the presence of confined bubbles of air or gas.n. A distortion of peach-leaves caused by the fungus Exoascus deformans; bladder-blight. See Exoascus. Also called blistering.To raise a blister or blisters on, as by a burn, medical application, or friction: as, to blister one's hands.To raise filmy vesicles on by heat: as, too high a temperature will blister paint; blistered steel. See blister-steel.Figuratively, to cause to suffer as if from blisters; subject to burning shame or disgrace.To rise in blisters, or become blistered.n. A swelling on a metal plate; a bag.n. A young oyster.n. In photography, a defect in a plate or on a paper in the process of coating with gelatin, albumin, or collodion.n. In glass-making, a defect in the glass caused by the retention of gas-bubbles formed during the melting.n. A common disease of pear-leaves produced by a mite, Phytoptus pyri, commonly called the pear-leaf blister mite. Each blister is a swelling of the leaf, producing a cavity in which the mites are found.