Word played college football at the University of Virginia. In 1985, he ran for 1224 yards, which is currently the fifth largest rushing yards total put up by a Virginia Cavaliers running back. Also in 1985, Word was the Atlantic Coast Conference player of the year. He was drafted in the 3rd round, 62nd overall, by the New Orleans Saints. In 1987, he and two other Virginia athletes were indicted on cocaine distribution charges. Word pleaded guilty, and his willingness to cooperate and his limited involvement in the case meant he only received 5 months in prison.
After Word’s release from prison, he signed a three-year contract with the Saints. He ran for 133 yards in 1987, his rookie year. In 1988, however, he found that he was the third-string running back for the Saints behind Rueben Mayes and Dalton Hilliard, two running backs drafted by the Saints before Word in the 1986 NFL Draft. He sat out the entire 1989 season before being picked up by the Kansas City Chiefs before the start of the 1990 season. Word had a career year in 1990, rushing for 1015 yards on 204 carries. He was given the NFL Comeback Player of the Year Award for his performance that season. He split carries with Christian Okoye during that season and for the following two seasons. At the end of the 1992 season, Word was traded to the Minnesota Vikings. He ran for 458 yards on 142 carries, which was second on the Vikings, a team that went without a 500-yard rusher that season. He was signed by the Cardinals at the start of the 1994 season. He only played one game, without a rush, and retired. He has said that being able to retire early is not a bad thing, and told Tiki Barber that as he was about to retire.