Walk The Line Meaning

(idiomatic, US, education) To participate in the procession at a graduation ceremony; to graduate.

Example: 1914, Julian Hawthorne, The Subterranean Brotherhood, ch. 13:
  I sat at dinner, but satisfied myself with nibbling bread crusts, and witnessing the forlorn and perilous efforts of my friends to walk the line between starvation and acute indigestion.
1992, "It's Twyla Time Again," Newsweek, 27 Jan.:
  I began to walk the line between work and play.
1956, Johnny Cash, "I Walk the Line," Sun Records:
  I keep a close watch on this heart of mine
  I keep my eyes wide open all the time
  I keep the ends out for the tie that binds
  Because you're mine, I walk the line.
To mark or secure a boundary by walking along it.
1914, Robert Frost, "Mending Wall":
  And on a day we meet to walk the line
  And set the wall between us once again.
2002, Gary Kubota, "Maui girl wins right to forget the dress," Honolulu Star-Bulletin, 7 May (retrieved 12 June 2008):
  A Baldwin High School student will be able to wear slacks to her graduation ceremony, under an order from the Maui School District. . . . "I'm very glad she'll be able to walk the line with her graduating class," Rosaga said.
2006, "Graduation 2006: Valedictorian seeks better life for her family," Valencia County News-Bulletin.com, 13 May (retrieved 12 June 2008):
  Montano's family, including her parents, sons and fiance, Thomas Gallegos, planned to be on hand to see her walk the line and be honored by the UNM-VC Advisory Board, faculty and staff and her fellow associate degree graduates.