At that point, it's better to move off the "grid" idea; if I'm looking for grid + reddit, I will not remember "griddet" or "grettid" (or was it grottid? regreddit? griblets?)

tetris + reddit = tetredd.is || tetredd.it ??

grid + reddit = gridddit.com || griddd.it

[all available at time of writing, checked on https://who.is]