Resumé My diploma thesis focuses on the slang of watermen. Slang is considered as a non-literary layer of national language, containing specific words that are used in common, especially informal, communication of people who share the same occupations or interests. The first part introduces the theoretical definitions of slang by prominent Czech linguists and the second part describes the aspects of slang. The third part gives us the characteristic of waterman slang from more points of view - setting, specific activity and collectivity. The fourth part focuses on the creation of words in waterman slang and the fifth part describes its specificity from the language point of view, including the distribution and productivity of individual onomasiological approaches. The last part contains a list of waterman slang words in alphabetical order with their grammar characteristic, meanings, synonyms (if possible) and the way how the word was formed.