That's a Google Adsense link. Website owners get paid each time you click on it and they have very little control over the content.

The links are chosen by: the content of the page, the success of the link, your physical location and many other attributes. For example, if you see a link whilst at Tallinn, it will be a different link when in Miami.

This normally means Google will display highly appropriate, geotargetted adverts in your own language but every now and then it will go wrong, and either latch on to some unusual phrase someone has used on the page or even an advertiser will simply select an incorrect word when creating their Google Adwords advert. Nothing to worry about.