Without a read on how aggressive villain is I'm happy to just fold and move on. He won't be bluffing here with a high enough frequency that makes our life tough. If we have position then it's much closer to a defend, but until you've seen him do this multiple times I wouldn't let it worry you.

Adjust to your opponents using the information available; don't drive yourself mad thinking an unknown player is just making random airball bluffs on a drawy board, because the average player won't play this way at 10NL. Believe me though, I'm as guilty as anyone for this!