1. One trouble leads to another that aggravates the first
   "The company's financial problems created a vicious circle of declining sales and increasing debt";
   - vicious cycle
    
2. An argument that assumes that which is to be proved
   "His reasoning fell into a vicious circle when he used the conclusion to prove one of his premises"

Derived forms: vicious circles

Type of: positive feedback, regeneration, specious argument

Encyclopedia: Vicious circle