The term 'Biblical Plague' refers to a series of disasters that were inflicted upon the ancient Egyptians by God as punishment for their refusal to free the Israelites. The plagues included frogs (5 letters), locusts (7 letters), boils (5 letters), and an unspecified plague of locusts (6 letters) and hail (4 letters). These plagues caused great destruction and suffering, ultimately leading to the release of the Israelites from captivity.