The legislation is being 'piggybacked' on another bill. [=is being added to another bill so that they will both be passed together]
Her father gave her a 'piggyback'. = Her father gave her a 'piggyback ride'. [=her father carried her on his back]
Other companies are trying to 'piggyback' on our success. [=trying to use our success to help themselves]
(..) of our best time together, just in case you get lonely. That's me and you making noodles. And that's me and you eating noodles. And that's me giving you a piggyback ride. That cute? On second thought, I'll hang on to this one. - Hey, they're waiting for me. - Of course, of course. (..)2011 Kung Fu Panda 2