digression/daɪˈgreʃn; daɪ`ɡrɛʃən/ n(a) [U] digressing 离题.(b) [C] passage, etc in which one digresses 题外话; 枝节内容 If you'll allow a slight digression,... 请允许我说几句题外话....
牛津英汉双解词典