pier

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A platform extending from a shore over water and supported by piles or pillars, used to secure, protect, and provide access to ships or boats.
• noun Such a structure used predominantly for entertainment.
• noun A supporting structure at the junction of connecting spans of a bridge.
• noun Architecture Any of various vertical supporting structures, especially.
• noun A pillar, generally rectangular in cross section, supporting an arch or roof.
• noun The portion of a wall between windows, doors, or other openings.
• noun A reinforcing structure that projects from a wall; a buttress.

from The Century Dictionary.

• noun A mole or jetty carried out into the sea, to serve as an embankment to protect vessels from the open sea, to form a harbor, etc.
• noun A projecting quay, wharf, or other landing-place.
• noun One of the supports of the spans of a bridge, or any structure of similar character.
• noun In architecture or building:
• noun The solid support from which an arch springs. See first cut under arch.
• noun In medieval architecture, a large pillar or shaft; specifically, a compound or a square pillar.
• noun One of the solid parts between openings in a wall, such as doors and windows.
• noun The wall or post, of square or other form, to which a gate or door is hung.
• noun In a physical laboratory or observatory, a structure, generally of masonry, designed by its stability to prevent vibration in instruments which are supported by it.

from the GNU version of the Collaborative International Dictionary of English.

• noun Any detached mass of masonry, whether insulated or supporting one side of an arch or lintel, as of a bridge; the piece of wall between two openings.
• noun Any additional or auxiliary mass of masonry used to stiffen a wall. See buttress.
• noun A projecting wharf or landing place.
• noun the pier of a bridge next the shore; a pier which by its strength and stability resists the thrust of an arch.
• noun a mirror, of high and narrow shape, to be put up between windows.
• noun a table made to stand between windows.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A raised platform built from the shore out over water, supported on piles; used to secure, or provide access to shipping; a jetty.
• noun A similar structure, especially at a seaside resort, used to provide entertainment.
• noun US, nautical A structure that projects tangentially from the shoreline to accommodate ships; often double-sided.
• noun A structure supporting the junction between two spans of a bridge.
• noun architecture A rectangular pillar, or similar structure, that supports an arch, wall or roof.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (architecture) a vertical supporting structure (as a portion of wall between two doors or windows)
• noun a support for two adjacent bridge spans
• noun a platform built out from the shore into the water and supported by piles; provides access to ships and boats