Before gee: pl

• Report card calamities
• Flunking letters
• Flunking grades
• The only grading letters that appear anywhere in this puzzle (other than the present clue)
• G.P.A. destroyers
• G.P.A. killers
• Affluent duo?
• A lot of fluff
• Pieces of fluff

Wiktionary Word definitions in Wiktionary
n. (plural of ef English), the name of the letter F.