The term USE A BLINKER can be broken down into two crossword solutions: SIGNAL and SLUSHY. A SIGNAL is a gesture or action that conveys a message or instruction, such as a hand SIGNAL or a light SIGNAL. A blinker is a type of SIGNAL that uses a flashing light to indicate a change in direction or to warn other drivers. SLUSHY is a term used to describe a semi-frozen mixture of snow and water, often found on roads during the winter months. Therefore, the phrase USE A BLINKER can be interpreted as a warning to use caution when driving in icy conditions.