Merriam-Webster's Collegiate® Dictionary, 11th Edition
DEFEAT
I. transitive verb see: do
Date: 14th century
destroy ,
2. nullify , frustrate 2a(1) , to win victory over ; beat , see: conquer defeatable adjective
II. noun
Date: 1590
frustration by nullification or by prevention of success , destruction ,
3. an overthrow especially of an army in battle, the loss of a contest