The term 'FRIGHTFUL Flies' can be broken down into two crossword solutions: 'Tsetses' (7 letters) and 'FRIGHTFUL' (9 letters). Tsetses are a type of fly found in the Mediterranean region, known for their bright colors and long wings. They are also known to carry diseases such as malaria and sleeping sickness. FRIGHTFUL is an adjective meaning causing fear or dread. Together, the two words describe a type of fly that is both colorful and potentially dangerous.