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How do you write the word semi transparent (meaning partially transparent)?

  1. semitransparent
  2. semi-transparent
  3. semi transparent

I found each of them on the Internet and none of them in my English dictionary.

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up vote 2 down vote accepted

The British National Corpus has 4 mentions of semitransparent, and none of either semi-transparent or semi transparent.

Wiktionary has an entry for semitransparent, but not for semi-transparent. Merriam-Webster has an entry for semitransparent and says that the first known use was in 1731.

(Google seems to be rather unreliable here: searching for "semi transparent" matches semitransparent and semi-transparent, and vice versa.)

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I tried to find the corresponding numbers from the Corpus of Contemporary American English, but got heartily tired of fighting with the interface and gave up. – Marthaª Oct 22 '10 at 19:27

The American Heritage Dictionary Fourth Edition includes “semitransparent”.

“semi-”, in this case, is being used a prefix rather than a word. Because of this, I would not use “semi transparent”.

Regarding “semi-transparent”, my understanding is that the hyphen tends to be dropped and the word elements combined to form a derivative word according to how common the combination is. Therefore, if I had not been able to locate it in the dictionary, then I would likely have used the hyphenated prefix.

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I know "semi-transparent" and "semitransparent" are both used, but normally I see it written as "translucent". Anyway, unless if you're writing a formal document, it doesn't matter because everyone will get it, and I wouldn't look at a dictionary because language changes faster than dictionary publications.

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“translucent” indicates distortion of the partially-blocked image, while “semitransparent” does not. – Jeffrey L Whitledge Oct 22 '10 at 16:12
@Jeffrey: I've never heard that meaning of "translucent" and my online dictionary search finds no such meaning. To me, translucent means "light goes through". Do you have a source for your definition? In my English Translucent and Semitransparent are synonyms. – Mr. Shiny and New 安宇 Oct 22 '10 at 19:02
The American Heritage Dictionary says "1. Transmitting light but causing sufficient diffusion to prevent perception of distinct images." I originally put "connotes" on my comment, but after I read the definition, I changed it to "indicates". – Jeffrey L Whitledge Oct 22 '10 at 19:07
@Jeffrey: I'd say "diffusion" is different than "distortion" – Mr. Shiny and New 安宇 Oct 25 '10 at 14:29
@Mr. Shiny and New - I would say that distortion includes diffusion. And though you may ding me for lack of specificity in my comment, it is clear that “translucent” is not the same as “semi-transparent”. – Jeffrey L Whitledge Oct 25 '10 at 20:50

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