According to NBC Sports, the Deerfield resident died at a after a battle with brain cancer.
From the article:
When he graduated in 1969, Seymour qualified as Notre Dame’s all-time leading career receiver – with 138 catches for 2,113 yards and 16 touchdowns in his three-year varsity career from 1966-68. He was listed on the College Football Hall of Fame ballot for 2011.
Seymour joined forces with quarterback Terry Hanratty and the two were nicknamed “Mr. Fling and Mr. Cling.” The legendary duo was featured on the cover of Time Magazine and helped secure the Irish a national championship in 1966.
According to the New York Times Seymour went on to play three years for the Chicago Bears.