digress/daɪˈgres; daɪ`ɡrɛs/ v[I, Ipr]~ (from sth) turn or wander (from the main topic) in speech or writing 说话或写作时偏离（主题）; 离题 Don't digress (from the subject) when lecturing. 讲课时不要岔开（主题）.
牛津英汉双解词典