HA! That's true, didn't make the connection between the two meanings sice I usually think of dumbass as baka or aho xD
Bokeh is the quality of the out of focus area in the picture. A good lens can produce sharp results in the area of focus, but can also produce beautiful blurring in the out-of-focus area, and that part is what is called bokeh.
Awesomely enough, the term bokeh is actually Japanese (暈け means "blur").