Answer:

bonedup

Answer	Crossword Clue
BONEDUP	Hit the books hard
BONEDUP	Crammed
BONEDUP	Studied intensely

BONEDUP	Crammed.
BONEDUP	Crammed for exams
BONEDUP	Studied in a hurry
BONEDUP	Took a refresher course

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.