The term 'Hazardous Pest' can be summarized by the crossword solution 'TSETSE', which is a genus of biting flies native to tropical and subtropical regions of Africa. These flies are known to transmit diseases such as sleeping sickness, which can be fatal if left untreated. TSETSE flies are considered to be a hazardous pest due to their ability to spread disease and cause discomfort to humans and animals alike.