At the moment, a whole words are removed from text until it becomes short enough to fit in the text box, and this is the only available behaviour.

There should be an option to put ellipsis or clip the text to the textbox width instead (like CSS text-overflow "ellipsis" and "clip").

There's also an older discussion here:
https://www.telerik.com/forums/request-ability-to-show-an-ellipsis-in-a-text-box-when-the-text-overflows-the-available-space