@sp1814
Yes, I posted in haste and subsequent googling just left me increasingly confused. Why have one word for something when we can have three, subtly different ones which only a few care to distinguish? QI explained it better. If I hadn't have seen that, I would have let your comment go.
I could get pedantic about typos: any five letter combination where one key was mishit would be a typo. Missing a letter completely is a spelling error. No biggie, except when people pretend it wasn't one. X-)
And then there are touch-screen keyboards, which are another story. If I type too fast (two fingers, on the mobile), letters do go awol. The mishit key possibilities are broadly similar but interestingly different in the vicinity of the H key.