Divagate and Excurse

Divagate verb - Lose clarity or turn aside especially from the main subject of attention or course of argument in writing, thinking, or speaking.

Excurse and divagate are semantically related In some cases you can use "Excurse" instead a verb "Divagate".

Divagate and excurse are semantically related in deviate topic. You can use "Divagate" instead a verb "Excurse", if it concerns topics such as stray, endlessly, go in different directions, wander about.