I think posting on the FAQ that users first check online dictionaries before posting these types of questions would be very helpful.
In my opinion a great example of an off-topic question is:
A 2 second google search would have revealed this answer. Not only do questions like this contribute nothing positive to the site, other than entertainment value, but they also have a negative impact as well. Users will think EL&U is nothing more than an online dictionary, just like some think SO is nothing more than a wiki. They will leave before giving the site a chance.
Why don't we encourage questions that demonstrate a minimal level of research? We should encourage questions that are practical, that solve a problem users could not easily solve in a couple seconds in another manner. I say we should close questions like this regardless of how popular they are.