SONSY Meaning of SONSY in English adj. (also sonsie) (sonsier, sonsiest) Sc. 1. plump, buxom. 2 of a cheerful disposition. 3 bringing good fortune. Etymology: ult. f. Ir. & Gael. sonas good fortune f. sona fortunate Oxford English vocab. Оксфордский английский словарь. 2012