piggybacking noun5 •Riding on someone else's back.No piggybacking or other horseplay is allowed in the hallways. •Transport involving vehicles arranged in an analogous way. •Joining in an activity that is initiated or led by someone else.Piggybacking on others' innovations seems to be his only plan for success. •The act or process by which someone piggybacks. •Inappropriately gaining entry into a restricted area, past a checkpoint, by tagging along behind another person who is authorized.The security team watches who comes through the door, and they will stop anyone who is seen piggybacking behind a badgeholder.