bolster

American  

[bohl-ster] / ˈboʊl stər /

noun

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. Nautical.

   1. Also called bolster plate.  a circular casting on the side of a vessel, through which an anchor chain passes.

   2. a timber used as a temporary support.

   3. a beam for holding lines or rigging without chafing.

   4. 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.

   1. a timber or the like connecting two ribs of a centering.

   2. 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.

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verb (used with object)

1. to support with or as with a pillow or cushion.

2. to add to, support, strengthen, or uphold (sometimes followed byup ).

   They bolstered their morale by singing.

   He bolstered up his claim with new evidence.

   Synonyms:

   fortify, reinforce, aid, sustain, strengthen

bolster British  

/ ˈbəʊlstə /

verb

1. (often foll by up) to support or reinforce; strengthen

   to bolster morale

2. to prop up with a pillow or cushion

3. to add padding to

   to bolster a dress

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noun

1. a long narrow pillow or cushion

2. any pad or padded support

3. architect a short horizontal length of timber fixed to the top of a post to increase the bearing area and reduce the span of the supported beam

4. a cold chisel having a broad blade splayed towards the cutting edge, used for cutting stone slabs, etc

Related Words

See cushion.

Other Word Forms

• bolsterer
  noun
• bolstering
  noun
• unbolster
  verb (used with object)

Etymology

Origin of bolster

First recorded before 1000; Middle English bolstre (noun), Old English bolster; cognate with Old Norse bolstr, Dutch bolster, German Polster

Explanation

When you cheer up a friend who's feeling down, you bolster them. To bolster is to offer support or strengthen. A bolster is also the name of a long pillow you might use to make your back feel better. And the two uses are not dissimilar. When you bolster your friends, you support them and prop them up, just like the pillow does for your back. When you're trying to bolster your credibility, you find people and/or documents that support you or your view. Bolster efforts to learn this word!

Example Sentences

After the public fallout from Callais, the justices went on press tours to bolster the court’s legitimacy.

From Slate • May 19, 2026

On Monday evening, Gov. Gavin Newsom announced that his office had secured a fire management assistance grant from the Federal Emergency Management Agency to bolster the response to the Sandy fire.

From Los Angeles Times • May 19, 2026

If tech founders want to stand out in an increasingly saturated and flattened market, they must bolster brilliant ideas by leaning on the one quality AI can’t emulate: humanity.

From The Wall Street Journal • May 18, 2026

These states might look at the agreement as a chance to bolster a somewhat shaky utility in Dominion with the help of a healthier one in NextEra, which has consistently delivered below-average costs, West added.

From Barron's • May 18, 2026

“Giddy-yap, Rainbow!” she cried aloud, to bolster her nerve, and also to warn any passersby of her wobbly, swerving approach.

From "The Hidden Gallery" by Maryrose Wood

Related Words

• aid
• boost
• buoy
• buttress
• cushion
• help
• maintain
• reinforce
• shore up
• strengthen
• support
• sustain