WordWeb Online

1. Aggressively challenge in speech or writing
   - attack, round, assail, snipe, assault
    
2. [Brit, informal] Spend money extravagantly, esp. to indulge oneself
   "I lashed out on a new TV";
   - splurge [informal], lash [Brit, informal], splash out [Brit, informal]

Derived forms: lashed out, lashes out, lashing out

Type of: consume, criticise [Brit], criticize, damn [informal], knock [informal], pick apart, squander, ware [archaic], waste