adjective/ˈt͡ʃat͡ʃi/
cool, terrific
Synonyms: bacán, bacano, bárbaro, buena onda, chachi, chachi pistachi, chulo, chido
Related: chachi piruli, chachi pistachi
Uncertain. Widely believed to be from Caló chachipén / chachipé (“truth”), a language spoken by the Spanish Romani. Another theory (which is presumably an urban legend) is that the term is derived from the surname of British prime minister Winston Churchill due to the quality of products coming from British-governed Gibraltar.