I researched this a while ago and can't remember how to do it. I want to be able to prevent Firefox from running it's spell-checking functionality on certain input fields from within the page. I know it's possible but can't remember how to set it up.
Talk about having a big "duh" moment! I found the answer after some trial & error:
<textarea spellcheck="false"></textarea>
The "spellcheck" attribute is currently an extra feature available only in Firefox, but it is being considered for inclusion in HTML5.
add the attribute using JQuery $('.textarea_className').attr('spellcheck',false);
This will allow you to return a valid XHTML mark up. =)
The downside of this is that the W3 strict validator gives - Attribute "spellcheck" is not a valid attribute. Bad news for those of us with OCD that love to see 0 errors in validating our sites.
来源：https://stackoverflow.com/questions/223940/inline-disabling-of-firefox-spellcheck