A super senior is a student in an American four-year educational institution such as a high school or university who has been attending the institution for 5 or more years or has more than the usual number of credits required to graduate without achieving a diploma or bachelor's degree.
Applied to education in the United States, super-seniors usually have the minimum number of credits to graduate but do not for various reasons. These students will advance through the grades (freshman, sophomore, junior- senior) on schedule and are classified as a "senior" for two or more years.
A student-athlete may have been made a redshirt their freshman year, which delays their four-year eligibility for competition in the NCAA until their sophomore year. As a result, they will still be eligible the year after their senior year and may stay in college to continue competition.
Students who intend to complete two or more degrees at the same time are often required to earn approximately 140-150 credits to receive their degrees, rather than the normal 120. It is often in the student's best interest to earn all desired/required undergraduate degrees at the same time as financial aid is more readily available to undergraduates than to graduates returning for additional undergraduate degrees. They could also use summer school sessions as well.
Students may choose to change majors after they are well advanced in their schooling. These students often have enough general education credits and overall credits to graduate but do not have their major-specific credits completed.
Students may take a leave of absence from their university for the difficult circumstances described below, or to pursue other endeavors, such as living, working, or studying abroad, tending to a fledgling business, or pursuing opportunities in their chosen career. Stanford University in particular is known for its sizable constituency of fifth-year (and sometimes even sixth-year) seniors who took time off to volunteer or work overseas. Many of Stanford's more famous alumni have taken a leave of absence and never returned to the school.
Another school well known in this regard is Brigham Young University, the flagship school of The Church of Jesus Christ of Latter-day Saints. Many male BYU students, both at the main campus in Utah and at its branch campuses in Hawaii and Idaho, take two years off during their studies to go on LDS missions. Before a 2012 change in church policy, female students were much less likely to take time off to serve missions (which, for women, last 18 months). Under the old policy, men were allowed to serve at age 19, while women had to wait until 21 (by which time many would be close to finishing degrees, married, or both). With the new policy, males can go on missions immediately after high school as long as they are at least 18, while females can serve once they turn 19.