Longman Dictionary English From Longman Dictionary of Contemporary EnglishRelated topics: CurrenciesC-noteC-note /ˈsiː nəʊt $ -noʊt/ noun [countable] American English informal PECa 100 dollar noteOrigin C-note (1900-2000) C “C-note” ((19-20 centuries)); because the Roman letter C (= 100) used to appear on 100 dollar bills ldoceonline.com