U-boat Tzu-chou • ubussu palm · · · Info · Definitions · Synonyms · Characters · · U-boat · · Text Common · · Latin · · Scripts 6 · · Length Definitions · · · (noun) a submersible warship usually armed with torpedoes. Synonyms: submarine, pigboat, sub. · · Noun Definition 1 Synonyms · · · submarine · · Synonym 1 pigboat · · Synonym 2 sub · · Synonym 3 Characters · · - hyphen-minus U+002D U latin capital letter u U+0055 a latin small letter a U+0061 b latin small letter b U+0062 o latin small letter o U+006F t latin small letter t U+0074