1. attacked or sunk by a submarine
Usage: nautical; military
2. undermined or sabotaged secretly
Usage: informal

Examples

• The cargo ship was submarined during the war.
• Three merchant vessels were submarined in the Atlantic.
• His proposal was submarined by colleagues who leaked details to the press.
• The project got submarined when funding was quietly withdrawn.
• The enemy convoy was submarined before reaching port.
• Her campaign was submarined by anonymous rumors.