If you've been on the internet for, oh, a few hours, you will inevitably encounter somebody using the word "arguably." And as someone who spends a fair amount of time online (an assumption I'm willing to make re: Slog readers), you've seen the word so often, you probably don't scrutinize its worthiness. But maybe it's time to examine how efficacious "arguably" actually is in written and spoken discourse.
Yes, "arguably" is a legitimate word that exists in every dictionary, but that doesn't mean it's going to bolster the quality of your writing and/or argument. As someone whose name escapes me wrote on a website whose URL eludes me over a dozen years ago, "Everything is arguable." Words to thrive by...
Now, you may argue against that assertion (*rueful chuckle*), but when you think hard about the subject, yes, damn near everything is arguable. (E.g., "This post is arguably Segal's most annoying yet." No shit. We could be here all day arguing about it.) And if that is the case, then "arguably" contributes as much to your sentence as parsley does to your dinner. Granted, it sounds and even feels good to use "arguably," but doing so adds zero value to your prose. It's dead weight.
In the lexscape of crimes visited upon English, as outlined here, here, here, and here, using "arguably" is minor. But abolishing it from your rhetorical arsenal would represent one small yet important step toward better, more streamlined communication.