Obnubilate is a verb that means to darken or obscure. 

The Latin word obnubilare (ob new be LAR ay) means ‘to hide’ or ‘to obscure.’ Since the late 16th century our word of the day has been carrying out the same function in English. Example:

People thought the scarf I was wearing was an attempt to be fashionable. But in truth, I was just hoping to obnubilate that coffee stain on my shirt. You’d be surprised how much of my clothing choices are really just attempts to mask my clumsiness.