F Russell wrote

The soil around one corner of my home has subsided
for about 12-18 inches. For a length of about 10-15
feet the top of the basement wall is exposed.

Is it safe to leave it like this

Depends on why it has subsided like that.

If there is a sink hole there, the whole house could
end up in the hole when it gets a lot worse.
https://www.google.com/search?q=sink...house&tbm=isch

or should I dump a load of dirt to raise the ground level?