English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In science we often invent words, but that doesn't mean we know how to spell them. Most of the time words are invented by adding prefixes. In that case should there be a hyphen or not? Specifically, I need to use

  • reexcite or re-excite (reentry is similar and a official word)
  • repolarize or re-polarization

The second seems fine in the no-hyphen form, but for the first, the double "e" makes the word difficult to read. I've seen similar use with a i diaeresis over the e: ë as in reëxcite, but that looks strange; any pointers?

share|improve this question
The "umlaut-e" version you are talking about is called [dieresis](en.wikipedia.org/wiki/Diaeresis_(diacritic)). It is not done the way you wrote it; the e would be written twice with the dieresis placed on the second e: i.e. "reëxcite". That said, I wouldn't use it. Dieresis is quite rare in today's English except for the word naïve, where it is more common, but still totally optional. (They do use them often in The New Yorker magazine, but this is very exceptional and somewhat pretentious, in my opinion.) – Kosmonaut Dec 31 '10 at 15:48
BTW, you mean hyphen, not dash. (There are two dashes in common usage, the [ en dash ](en.wikipedia.org/wiki/Dash#En_dash) and the [ em dash,](en.wikipedia.org/wiki/Dash#Em_dash) both longer than a hyphen.) – ShreevatsaR Dec 31 '10 at 15:51
Thanks to both @Kosmo and @Shree, I updated my question. – Yossi Farjoun Dec 31 '10 at 16:20
up vote 8 down vote accepted

It depends on how recent the words are. If you are concerned that your meaning will be unclear, by all means use the hyphen. Words like reentry and reelect have been in usage for a long time and pretty much no one has a problem with them. Reexcite has not, so you would do better to stick with re-excites. If you want to edit something again, you are probably better off to re-edit it if you are worried that reedit will cause the reader to stumble.

Where the prefix is not followed by a vowel, however, you are not honor-bound to add the hyphen. If you want to repolarize something, go right ahead. According to Etymonline, the word repurpose is less than 30 years old, having dropped its hyphen somewhere in the early 1980s. So if you are the first to repolarize something, you are not likely to be the last, and you will probably start a trend. In any case, your meaning will be clear.

share|improve this answer
In general, use a hyphen if it aids readability: this point is somewhat important when writing material that is to be consumed by people who might not be ultra-comfortable with English. – Suvrit Dec 31 '10 at 16:22

The only thing to add to Robusto's answer is that sometimes there's no choice but to keep the hyphen, to prevent confusion. For example, recover ("get something back") vs. re-cover ("cover again").

share|improve this answer

There are two tests for deciding:

First, which way do most of your colleagues do it, reparameterized or re-parameterized?

Generally, it's standard operating procedure (SOP) to imitate your peers and colleagues because that's what they expect to see.

Second, will the version without the hyphen cause confusion or force the reader to waste time by having to look at the word a second time?

If the outcome of the second test is Yes, then use the hyphen.

There may be a third test. British English writers generally use hyphens more often than American English writers. If you're writing for a European journal or an audience of British English speakers, it might be better to use the hyphen. If the audience is primarily American, it might be better to omit the hyphen.

I don't think there should be any confusion without the hyphen, but that's just a personal opinion. Ask a couple of colleagues how they would write it.

share|improve this answer
Good observations and suggestions. Thanks. – Sigur Oct 18 '12 at 10:36

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.