dim sum Syllabification: (dim sum)Pronunciation: /ˈdim ˈsəm/Definition of dim sum noun a Chinese dish of small steamed or fried savory dumplings containing various fillings, served as a snack or main course. Origin:from Chinese (Cantonese dialect) tim sam, from tim 'dot' and sam 'heart'dim sum in other Oxford dictionaries Definition of dim sum in the British & World English dictionary