The term 'Abyssmal Grade' is a phrase used to describe a very low score or grade. The crossword solutions for this term are ZERO (4 letters), EFS (3 letters), and Zeros (6 letters). ZERO is a numerical value that indicates the absence of any quantity, while EFS stands for 'Extremely Failing Standard' and Zeros is the plural form of ZERO. Together, these three words provide an accurate description of an extremely low grade.