Definition of defeats:
(v) :
(transitive) To overcome in battle or contest.
(n) :
The act or instance of being defeated, of being overcome or vanquished; a loss.
(n) :
The act or instance of defeating, of overcoming, vanquishing.
(v) :
To prevent (something) from being achieved.
(v) :
(transitive) To reduce, to nothing, the strength of.
(v) :
(transitive) To nullify