ironside

UK: /ˈaɪənˌsaɪd/ US: (ī′ərn sīd′)

WordReference Random House Unabridged Dictionary of American English © 2025

i•ron•side  (ī′ərn sīd′), n. 

1. a strong person with great power of endurance or resistance.
2. Biographical (cap.) an epithet or nickname of Edmund II of England.
3. Biographical (cap.) Usually, Ironsides. 
   • (used with a sing. v.) a nickname of Oliver Cromwell.
   • the soldiers serving under Cromwell.
4. Nautical ironsides, (usually used with a sing. v.)
   • , Dialect Terms, Naval Terms an ironclad.
   • , Dialect Terms, Naval Terms [Eastern U.S.] scup.

• 1250–1300; Middle English; see iron, side¹

Collins Concise English Dictionary © HarperCollins Publishers::

Ironside / ˈaɪənˌsaɪd/ noun

1. nickname of Edmund II of England
   See Edmund II