Backslide and Come back

Backslide verb - Drop to a lower level, as in one's morals or standards.

Come back and backslide are semantically related. In some cases you can use "Come back" instead a verb "Backslide".

Come back verb - To become healthy and strong again after illness or weakness.

Backslide and come back are semantically related. Sometimes you can use "Backslide" instead a verb "Come back".