2. Noun. (idiomatic historical) During World War II, any of various marauding groups of submarines, especially German submarines that patrolled the North Atlantic and preyed upon merchant ships. ¹
¹ Source: wiktionary.com
2. Noun. (idiomatic historical) During World War II, any of various marauding groups of submarines, especially German submarines that patrolled the North Atlantic and preyed upon merchant ships. ¹
¹ Source: wiktionary.com