Find a concrete singular noun such that a search for "sexy _____" (in quotes) has 0 hits on google.
If you feel obliged to post your clever solutions as comments, please also post how many tries it took you to reach 0.
Update: If you are clever enough to get it in one, congratulations. You might poke around and try a few other things, to see what all the fuss is about. (For example, consider "ballista".)