Set back and Slow down

Set back verb - Hold back to a later time.

Slow down and set back are semantically related in delay topic. In some cases you can use "Slow down" instead a verb "Set back".

Slow down verb - Lose velocity; move more slowly.

Set back and slow down are semantically related in hold topic. You can use "Set back" instead a verb "Slow down", if it concerns topics such as stick, delay, hinder, postpone.