|1.||any N temperate betulaceous shrub or tree of the genus Alnus, having toothed leaves and conelike fruits. The bark is used in dyeing and tanning and the wood for bridges, etc because it resists underwater rot|
|2.||any of several similar trees or shrubs|
|[Old English alor; related to Old High German elira, Latin alnus]|
Alder Al·der (äl'dər), Kurt. 1902-1958.
German chemist. He shared a 1950 Nobel Prize for discoveries concerning the structure of organic matter.