"Division I" is name given to the most competitive level of intercollegiate athletics in the United States. The division along with other less competitive divisions (II and III) are overseen by the National Collegiate Athletic Association.
How It's Used
“The Seattle Center, which houses KeyArena, recently lost the Seattle Thunderbirds minor league hockey team, but will host Seattle University basketball this season as the team moves to Division I.”
"In the five-year period through 2008, only 18 of 119 Division I athletic departments operated in the black, according to preliminary numbers compiled by Dan Fulks, an accounting professor at Transylvania University in Lexington, Ky., who has been an NCAA consultant for 20 years. Those numbers were before the economic downturn."