The term FIRE TRUCK ALERT is composed of two words, FIRE TRUCK and ALERT. The first word, FIRE TRUCK, refers to a vehicle that is used by firefighters to transport personnel and equipment to the scene of an emergency. The second word, ALERT, is a warning signal that is used to indicate danger or an emergency situation. The crossword solution for this term is SIREN, which is a loud, high-pitched sound that is used to ALERT people of an emergency.