I got a note last week from a correspondent asking me about the word hithertofore, and whether or not it was a ‘proper word’. I have to admit that at first glance I was very surprised, because of course it was a perfectly good word, and one whose meaning I knew well. But when the correspondent said that she’d looked around and hadn’t found it, I looked at it again and realized that of course it wasn’t a word. Or was it?
English has two words with a distinctly archaic flavour that mean ‘up to the present time’, hitherto and heretofore. These synonyms also start with the same letter, are compounds containing to, and to top it all off, hither and here are also synonyms, so it’s not even semantically odd. Neither word is especially common, and as you can see from this Ngram, hitherto and heretofore are really quite rare and becoming rarer. It’s hardly surprising, then, that some speakers and readers might blend these two. Whether we think of it as adding -fore to hitherto, or substituting hither for here in heretofore, doesn’t much matter, as the result is the same, hithertofore.
What should perhaps be more surprising is that hithertofore hasn’t hithertofore been included in any dictionary, not even with a usage note. It’s not hard to find in use in printed books; Google Books claims 67,500 works containing it (although that number is probably inaccurate) in lots of different genres. There are plenty of words in big unabridged dictionaries that are far less common than that. I’ve found it going back at least as far as 1708, and I didn’t have to look very hard. While it seems at a glance that a higher than average proportion of these works are authored by non-native English speakers, I also would argue that one has to be relatively fluent to even make such an error, conflating two already-unusual words.
Note, though, that its Ngram, rather than slowly declining from the 19th century until today like those of its two constituents, shows it to be largely a product of the mid-20th century, peaking around 1970. This suggests, firstly, that perhaps it was at its most popular when its two constituents had declined enough in frequency that they had fallen out of regular use (and were thus prone to confusion), but were still common enough to be intermixed. It hit its sweet spot half a century ago, but now the two well-accepted words themselves are falling out of use in favour of previously or other terms, so hithertofore may actually have lost its chance to become another widely used variant (even at its most popular, it was less than 1% as frequent as heretofore). I still think it’s a neat example of the way that memory, meaning, and phonology can lead to the appearance of nearly-invisible blends, and given that it is a relatively common error, it could probably use some lexicographical attention.