打(ぶ)ちのめすto knock (someone) down, to floor, to beat up, to beat to a pulp

う-verb (す), Transitive verb

1. 1.

   to knock (someone) down, to floor, to beat up, to beat to a pulp

   Colloquial, Usually written using kana alone

2. 2.

   to deal a devastating blow (from which one cannot recover), to devastate (emotionally), to crush, to overwhelm, to defeat resoundingly, to give (an opponent) a drubbing

   Colloquial, Usually written using kana alone