baluster

thumb|upright|Illustration of various examples of balusters, in A Handbook of Ornament, by Franz S. Meyer thumb|upright|The term derives from the swelling form of the half-open flower of Punica granatum, in Italian balaustra

A baluster () is an upright support, often a vertical moulded shaft, square, or lathe-turned form found in stairways, parapets, and other architectural features. In furniture construction it is known as a spindle. Common materials used in its construction are wood, stone, and less frequently metal and ceramic. A group of balusters supporting a guard railing, coping, or ornamental detail is known as a balustrade.