digress
v.
1520s, from Latin digressus, past participle of digredi "to go aside, depart" (see digression), or perhaps a back-formation from digression. Related: Digressed; digressing.
〔蒋〕[di-=dis-离开，gress行走;’离正道而行”] 离开主题，入歧路
〔李〕[di-(dis-)=aside偏离；gress=to step迈步→“to step aside步伐偏离”→] v. depart from the main subject 离开主题