shim: a thin wedge of material (wood or metal or stone) for driving into crevices
wedge: something solid that is usable as an inclined plane (shaped like a V) that can be pushed between two things to separate them
gastrocybe lateritia: a species of Gastrocybe fungus that has a conic cap and a thin stalk; at first the stalk is upright but as it matures the stalk bends over and then downward; the cap then gelatinizes and a slimy mass containing the spores falls to the ground as the stalk collapses