(This is not a question per se, I'm documenting a solution I found using Ext JS 3.1.0. But, feel free to answer if you know of a better solution!)

The Column config for an Ext JS Grid object does not have a native way to allow word-wrapped text, but there is a css property to override the inline CSS of the TD elements created by the grid.

Unfortunately, the TD elements contain a DIV element wrapping the content, and that DIV is set to white-space:nowrap by Ext JS's stylesheet, so overriding the TD CSS does no good.

I added the following to my main CSS file, a simple fix that appears to not break any grid functionality, but allows any white-space setting I apply to the TD to pass through to the DIV.

.x-grid3-cell {
    /* TD is defaulted to word-wrap. Turn it off so
       it can be turned on for specific columns. */
    white-space:nowrap;
    }

.x-grid3-cell-inner {
    /* Inherit DIV's white-space from TD parent, since
       DIV's inline style is not accessible in the column
       definition. */
    white-space:inherit;
    }

YMMV, but it works for me, wanted to get it out there as a solution since I couldn't find a working solution by searching the Interwebs.