Fourth-yr. students

• Promgoers, often: abbr
• Frat ldrs., probably
• Students with 300 and 400 classes: Abbr
• Last-yr. high schoolers
• Ones soon to leave the ivied halls: Abbr
• Univ. higher-ups
• H.S. students who often slack off in the spring
• Undergrads: Abbr
• Cap and gown renters: Abbr

Wiktionary Word definitions in Wiktionary
abbr. (context texting chatting English) (abbreviation of serious English)