(verb) 1. to expend by use; use up. Cities consume a high percentage of a countrys energy, due to the high populations living there. 2. to eat or drink up; devour. Many people consume a great deal of junk food. 3. to destroy, as by decomposition or burning: Fire consumed the forest. on a regular basis. 4. to spend (money, time, etc.) wastefully. 5. to absorb; engross: consumed with curiosity.