The Rice University Neologisms Database

The act of studying or doing school-related work through an entire night. This term seems to be widely used and accepted among students, and it is the most concise way of stating that someone spent the entire night studying or working. A night spent awake studying or doing homework. The suffix ‘-er’ seems to have no specified meaning. An ‘all-nighter’ does not refer to a person who stays up all night, but rather to the night itself. In this case, ‘-er’ seems to simply indicate that the word is a noun.