Pronunciation: (bōl'stur),[key] —n. 1. a long, often cylindrical, cushion or pillow for a bed, sofa, etc.
2. anything resembling this in form or in use as a support.
3. any pillow, cushion, or pad.
4. Naut. a. Also called bol'ster plate". a circular casting on the side of a vessel, through which an anchor chain passes.
b. a timber used as a temporary support.
c. a beam for holding lines or rigging without chafing.
d. a bag filled with buoyant material, fitted into a small boat.
5. Metalworking.an anvillike support for the lower die of a drop forge.
6. Masonry. a. a timber or the like connecting two ribs of a centering.
b. a chisel with a blade splayed toward the edge, used for cutting bricks.
7. Carpentry.a horizontal timber on a post for lessening the free span of a beam.
8. a structural member on which one end of a bridge truss rests.
—v.t. 1. to support with or as with a pillow or cushion.
2. to add to, support, or uphold (sometimes fol. by up): They bolstered their morale by singing. He bolstered up his claim with new evidence.