負かす is read as まかす (makasu) and means to defeat.
まかす
makasu
まけ
failing to live up to (one's name, looks, etc.)
おう
to have (something) behind one
まける
to be inferior to
おいめ
(feeling of) indebtedness
まけいぬ
unmarried and childless older woman
ふ
negative
まけこし
having more losses than wins
まけんき
competitive spirit
ふのがいぶせい
negative externalities
まけとうしゅ
losing pitcher
ふどうさん
unsellable property
まけとうしゅになる
to suffer a loss (usu. in sport)