Hyphenation and <nobr>

I need to hyphenate all text in one ePub, and I see it’s possible from preferences menu. Good.
Now, is there any way to not hyphenate a single word?
My first idea was inserting html code directly in the book, but this way fail, the compiler translate the html code in a simple text.
Any other idea?

Actually it is not possible to hyphenate on any e-reader device to my knowledge. I believe some do, but this is a function of the individual device’s display coding, not anything that is set within the e-book file itself—in a similar vein to how the device will set the background and text colour, screen margins, line-height, and typically the font. There is a CSS control for enabling browser hyphenation, but e-reader browsers universally ignore it. Hyphenation in an HTML-based environment has never been terribly good, but it is getting gradually better. I expect the e-book revolution to accelerate that.

The hyphenation option you are referring to in the Editor preferences pane is display-only. If you prefer to work in a fully justified text column, this option will greatly improve the readability of the text. As with all of the settings in the Editor pane, these have no bearing on your final output. Output parameters are set up in the Compile pane. Hyphenation can be enabled for some of the word processor formats that support it.

AmberV, thanks a lot for your answer.
Your explanation is really excellent!