Merriam-Webster Collegiate Dictionary - annihilate

 verb  (-lated; -lating)  Etymology: Late Latin annihilatus, past participle of annihilare to reduce to nothing, from Latin ad- + nihil nothing — more at nil  Date: 1525  transitive verb  1.  a. to cause to be of no effect ; nullify  b. to destroy the substance or force of  2. to regard as of no consequence  3. to cause to cease to exist; especially kill  4.  a. to destroy a considerable part of bombs ~d the city ; to vanquish completely ; rout ~d the visitors 56-0  5. to cause (a particle and its antiparticle) to vanish by annihilating  intransitive verb of a particle and its antiparticle to vanish or cease to exist by coming together and changing into other forms of energy (as photons)  • annihilation noun  • annihilator noun  • annihilatory adjective