vexatious russian

• кля́уза

  petty denunciation, tale-telling complaint, informing

  slander, malicious gossip, backbiting

  intrigue, scheming

  cavil, vexatious litigation, legal quibbling

• сутя́жничество

  litigiousness, vexatious litigation, malicious litigation

  quarrelsomeness, contentiousness, querulousness