Bit off-topic - macOS has excellent built-in dictionary. Just select the word in any app, press Ctrl+Command+D and it opens it. It even guesses most incorrect words correctly. Also translation available if it exist for current keyboard locales.

E.g.

> No entries for "typoglycemia", did you mean "hypoglycemia"?

These user activated dictionaries tend to be excellent (even in vim, a pretty barebones system, I tend to get fantastic guesses from the machine).

Actually, come to think of it, the problem must be a bit easier than on smartphones, right? Real keyboard input is very precise. Smartphone keyboards already guess what word you were trying to spell, so they are influencing the typos in the direction of likely words… cannibalizing the very guess list that the dictionary uses!

Alfred ties into it nicely too, you can type `spell someword` and the completions below have the various spellings of words, fuzzy matched. Select one and the word goes onto your clipboard

that's great. I usually use the context menu on MacOS and the "Define" option on long press on iOS

That said, trying to use long press on iOS (or whatever it actually is), is one of those places that often drives me nuts. I don't know if the issue is a specific app or the OS or what but sometimes I want the popup menu to appear and I can't get it to appear. Or I do something to make it appear but it doesn't appear for x hundred milliseconds, during which I think it didn't get my gesture so I start a new one, just as it's finally responding in which case my new gesture dismisses it. Repeat 3-4 times before I'm ready to tear my hair out

It also shows why canvas based websites suck. Open Google Docs, select a word, press Cmd-Ctrl-D, ... nothing. Try it in gmail (which is not canvas based) and it works.

There's also a gesture. Triple three finger tap or some such like.