cantaliver

from The Century Dictionary.

• noun A block or large bracket of stone, metal, or wood, framed into the wall of a building, and projecting from it, to support a molding, a balcony, eaves, etc. Cantalivers serve the same end as modillions and brackets, but are not so regularly applied.
• noun One of two long brackets or arms projecting toward each other from opposite banks or piers, serving to form a bridge when united directly or by a girder.
• Formed on the principle of the cantaliver, or with the use of cantalivers.