(nautical) The "trapped" condition a sailing ship finds itself in when the bow of the ship is headed into the wind and the ship has stalled and is unable to maneuver.
The state of screw-powered ships which become stalled between crests of waves or swells during a typhoon, for instance, and the ship's rudder does not respond to the commands from the helm, leaving the ship at the mercy of the sea and in danger of capsizing.
Source: en.wiktionary.orgA phrase to help remember this is: "light jibe, hard tack" (light/hard referring to wind strength) Of course being caught in irons near shore/structures in strong wind can be catastrophic. Source: Internet
The latter is a direct order to the helmsperson to push the tiller hard to the leeward side of the boat making the bow of the boat come up and quickly turn through the eye of the wind to prevent the boat being caught in irons. Source: Internet
Behind bars, and in irons, were Francisco Lugo Sr., Francisco Lugo Jr., and Mariano Elisalde, suspected of murder based on the uncorroborated statement of a jailhouse informant, Ysidro Higuera, a convicted horse thief. Source: Internet
Some of the men put in irons expressed themselves willing to return to duty when they saw the officer from the cutter board the vessel with his men; but Capt. Bidwell deemed it prudent to keep them in irons for a few days.” Source: Internet
Isaac surrendered and was confined with silver chains because Richard had promised that he would not place him in irons. Source: Internet