The term 'bombinate' is derived from the Latin word 'bombinare, ' which means to BUZZ or HUM. It is used to describe a low, continuous humming or buzzing sound. The crossword solutions for this term are HUM (3 letters), DRONE (5 letters), and BUZZ (4 letters). HUM is a low, steady sound made by vibrating the lips, DRONE is an aircraft without a pilot, and BUZZ is a low, continuous humming or buzzing sound. All three words can be used to describe the sound of bombinate.