CougarLife.com -- a dating service that matches older women with younger men -- posted the billboard with an image of a scantily clad woman and the German word on a billboard off Route 88 in the city's Overbrook neighborhood.
The billboard company said it has fielded complaints about the advertisement from passersby and the restaurant atop which it sits, the Royal Place Restaurant.
"We have a lot of families that come down here to eat. I hope it doesn't affect our business," restaurant chef Tony Libera said, noting the placement gives some people the impression his business sponsored the ad.
A company spokesman told WPXI-TV, Pittsburgh, a miscommunication with its advertising agency led to the billboard going up in the city.
The ad was not meant for use in the United States but a version of it was to be used in Germany, and the agency sent the wrong file to a printer who did not know what the word translated to in English.
"Cougarlife.com unreservedly apologies to the citizens of Pittsburgh for the erroneous advertising campaign that was recently unveiled in the Steel City," said Paul Keable, vice president of communications at Avid Life Media, which operates CougrLife.com, Ashley Madison, and other dating sites.
The report did not specify which offensive word was displayed on the billboard.