'Old Ironsides' definitions:

Definition of 'Old Ironsides'

(from WordNet)
noun
A United States 44-gun frigate that was one of the first three naval ships built by the United States; it won brilliant victories over British frigates during the War of 1812 and is without doubt the most famous ship in the history of the United States Navy; it has been rebuilt and is anchored in the Charlestown Navy Yard in Boston [syn: Constitution, Old Ironsides]

Definition of 'Old Ironsides'

From: GCIDE
  • Ironsides \I"ron*sides"\, n. A cuirassier or cuirassiers; also, hardy veteran soldiers; -- applied specifically to Cromwell's cavalry.
  • Old Ironsides. (U. S. Hist.) A nickname for the U.S.S. Constitution, a sailing ship which fought in the American Revolutionary war, and now functions as a floating museum in Boston harbor. It was given its nickname because cannonballs bounced off its hard wooden sides. [PJC]