buttress

UK: /ˈbʌtrəs/ US: /ˈbʌtrɪs/ ,(bu′tris)

WordReference Random House Learner's Dictionary of American English © 2025

but•tress /ˈbʌtrɪs/   n. 

[countable]
1. Building, Architecture a support that sticks out from the wall of a building to keep it steady:
   the buttresses of the old cathedrals in England.
2. any prop or support:
   the buttresses of civilized society.

v. [~ + object]

3. Architecture to support by means of a buttress;
   prop up:
   The builders buttressed this wall with stone structures that are marvels of engineering.
4. to give support or encouragement to:
   Try to buttress the points you make in these chapters with some details.

WordReference Random House Unabridged Dictionary of American English © 2025

but•tress  (bu′tris), n. 

1. Building, Architecture any external prop or support built to steady a structure by opposing its outward thrusts, esp. a projecting support built into or against the outside of a masonry wall.
2. any prop or support.
3. a thing shaped like a buttress, as a tree trunk with a widening base.
4. Zoology a bony or horny protuberance, esp. on a horse's hoof.

v.t. 

5. Architecture to support by a buttress;
   prop up.
6. to give encouragement or support to (a person, plan, etc.).

• Gmc; see butt³) + -et -et
• Middle English butres Old French (arc) boterez thrusting (arch) nominative singular of boteret (accusative), equivalent. to boter- abutment (perh. 1350–1400

but′tress•less, adj. 
but′tress•like′, adj. 
Synonyms

• 6. encourage, hearten, support, inspirit, brace, back up, reinforce, shore up.

Collins Concise English Dictionary © HarperCollins Publishers::

buttress / ˈbʌtrɪs/ noun

1. Also called: pier a construction, usually of brick or stone, built to support a wall
   See also flying buttress
2. any support or prop
3. something shaped like a buttress, such as a projection from a mountainside

verb (transitive)

1. to support (a wall) with a buttress
2. to support or sustain

Etymology: 13th Century: from Old French bouterez, short for ars bouterez thrusting arch, from bouter to thrust, butt³