I have noticed football commentators in Britain using the phrase just about when a player is successful as in "He just about made that pass". In AmE just about would mean "close but no cigar".Indeed, for the 'did make it, but only by a small margin' meaning, AmE could just use just: He just made it into the goal. But we might even avoid that, since that could also mean 'a moment ago'. This ambiguity is probably more of a problem in AmE than in BrE because of the differences in past-tense marking. I'd probably say only just in this context, but I'm fairly contaminated by BrE at this point. The Cambridge Dictionary of American Idioms gives only the meaning 'very recently' for only just. The two instances of only just made it in the Corpus of Contemporary American English (COCA) are 'very recently' and the eight in the much smaller British National Corpus all mean 'barely'. I think this has firmly diagnosed my BrE contamination. I'll have to tell my American family to wear protection around me.
I must admit, I'm held back a bit* in my discussion here by a couple of things. First, finding examples of particular meanings of just about is not exactly easy. If you search for the two words in a corpus or on the web, you will find huge numbers of examples, most of them irrelevant--it's just about how common the words are (see what I did there?). So I've had to look for bigger stretches of text, like just about made it, in order to limit the results to useful ones. That means that anything interesting that I didn't think of, I didn't find. Second, we were supposed to (AmE/BrE) move/(BrE) move house this week. We discovered Monday that we were not moving (house) this week, or indeed next week, or indeed this month. So all my books are packed (not the greatest of the current inconveniences!), and therefore I can't consult a couple of things that might have been helpful. I will blog about English (BrE) estate agents/(AmE) real estate agents and the horrors (and vocabulary!) of buying/selling property in England after this nightmare is over.
At any rate, the translation problem in just about isn't just about just. Let's think about about. The (UK) Collins English Dictionary gives us this sense-definition, which is not to be found in the American Heritage Dictionary or Merriam-Webster:
7. used in informal phrases to indicate understatement I've had just about enough of your insults it's about time you stopped
Aha, the famous British understatement. Rather than saying I've had enough, you put an about in to soften the blow. And then a just to soften it more.
But one would say I've had just about enough of your insults in AmE too. In fact, in COCA, there are 35 instances of about had it, including 16 just about had it. There might be a difference in perception here. To my AmE ear, I've just about had it is not an understatement. It means, if things don't change right away, I will have had it, and it's thus used as a warning. Whether BrE ears perceive that particular example as understatement is something that the mouths (or the typing fingers) that share a brain with those ears will have to tell us. At any rate, the UK dictionary did feel the need to mention it as an understatement-marker and the US ones did not, and I think there's something to that.
Ron's example is a much clearer case of understatement. The claim is that the pass was made, but it is stated as if the pass was not quite made in order to communicate that it almost wasn't made.
To give a few more examples, found by Google-searching "just about made it" (plus 'British' and 'American', because I originally searched with the hope that I'd find some dialect commentary):
We just about made it through Christmas. (Temple Audio, Ltd)There are also examples of the (orig. AmE) 'close but no cigar' type on this search and (of course) some that are ambiguous. But the above examples all come from the first page of results, clearly describe events that did happen (rather than ones that almost happened), and are all related (at least) to the UK. (The second is located in the US, but is a music scout who seems particularly Europe-focused, so one can only guess about his nationality or his linguistic contamination level.)
Well, I just about made it to hunt out some British talent for you all this week. I've tried to include more variety this time... (Road Runner Records)
I think you just about made it to the studio in time for your show! (commenter on Simon Mayo's BBC Radio 2 blog)
And on that note, I'm about finished.
* My ubiquitous bits are further evidence of my contamination. And yes, that is a double entendre. But don't think about it too much, please.