"substantially weaken" — Kollokationen-Wörterbuch Englisch

substantially weaken Kollokation
Beliebtere Konjugation: substantially weakened
Automatische Übersetzung (wir garantieren seine Korrektheit nicht): znacznie osłab
  1. weaken Verb + substantially Adverb
    Schwache Kollokation

    They may well feel the case against your brother is substantially weakened by what's come to light.