bulwark

UK: /ˈbʊlwə^rk/

US: /ˈbʊlwɚk, -wɔrk, ˈbʌl-/

US: (bŏŏl′wərk, -wôrk, bul′-)

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

bul•wark /ˈbʊlwɚk, -wɔrk, ˈbʌl-/   n. [countable]

1. a wall of earth or other material built for defense;
   rampart.
2. any protection against danger, injury, or annoyance.
3. a person or thing that gives strong support or encouragement.

WordReference Random House Unabridged Dictionary of American English © 2025

bul•wark  (bŏŏl′wərk, -wôrk, bul′-), n. 

1. a wall of earth or other material built for defense;
   rampart.
2. any protection against external danger, injury, or annoyance:
   The new dam was a bulwark against future floods.
3. any person or thing giving strong support or encouragement in time of need, danger, or doubt:
   Religion was his bulwark.
4. Nautical, Naval Terms Usually, bulwarks. a solid wall enclosing the perimeter of a weather or main deck for the protection of persons or objects on deck.

v.t. 

5. to fortify or protect with a bulwark;
   secure by or as if by a fortification.

• Middle Dutch bolwerc, equivalent. to bol(l)e bole¹ + werk work (noun, nominal); compare boulevard
• late Middle English bulwerk, probably 1375–1425

Synonyms

• 3. support, buttress, mainstay.

Collins Concise English Dictionary © HarperCollins Publishers::

bulwark / ˈbʊlwək/ noun

1. a wall or similar structure used as a fortification; rampart
2. a person or thing acting as a defence against injury, annoyance, etc
3. (often plural) a solid vertical fencelike structure along the outward sides of a deck
4. a breakwater or mole

verb

1. (transitive) to defend or fortify with or as if with a bulwark

Etymology: 15th Century: via Dutch from Middle High German bolwerk, from bol plank, bole¹ + werk work