1. An incandescent particle, especially: 2. One thrown off from a burning substance. 3. One resulting from friction. 4. One remaining in an otherwise extinguished fire; an ember. 5. A glistening particle, as of metal. 6. A flash of light, especially a flash produced by electric discharge. 7. A short pulse or flow of electric current. 8. A trace or suggestion, as: 9. the spark of genius. 10. the spark of revolution. 11. A radio operator aboard a ship. 12. The luminous phenomenon resulting from a disruptive discharge through an insulating material. 13. The discharge itself. 14. To give off sparks. 15. To give an enthusiastic response. 16. To operate correctly. Used of the ignition system of an internal-combustion engine. 17. The incident sparked a controversy. 18. A cheering crowd sparked the runner to triumph.
