A sculptural and an architectural term with several possible meanings. It is most commonly a platform extending from a shore over water and supported by piles or pillars, used either as a mooring for ships or boats, or for entertainments of other sorts. And finally, it may be any of several sorts of vertical supporting structures: such as a massive vertical pillar (rectangular, round, or compound in cross-section), a buttress; a section of wall that is used to support an arch, vault, or other kind of roof, or, a supporting structure at the junction of connecting spans of a bridge.(pr. peer)Related link: The Glossary of Medieval Art and Architecture has a definition and illustration of piers. Also see column, fenestration, and socle.