Backslide and Falls

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

Falls and backslide are semantically related In some cases you can replace term "Falls" with "Backslide", this verbs are similar.

Falls noun - A steep descent of the water of a river.

Backslide and falls are semantically related in descend topic. Sometimes you can use "Backslide" instead a verb "Falls".