HITS THE BOOKS is an idiom that means to study hard and with great effort. The crossword solutions for this term are CRAMS (5 letters), STUDIES (7 letters), and PORES (5 letters). CRAMS means to cram for a test or exam, which is to study a lot of material in a short amount of time. STUDIES means to study something in depth, often over a long period of time. PORES means to read something carefully and thoroughly. All three words imply a great deal of effort and dedication to learning.