A discharge or suppuration (pus formation) within the abdominal cavity.
From Greek koilia (belly) + pyesis (suppuration, pus formation). The root 'pyo-' appears in many medical terms related to pus and infection.
An infection spreading through your abdomen would be life-threatening, which is why ancient doctors developed terms to describe these dangerous conditions they couldn't yet treat!
Complete word intelligence in one call. Free tier — 50 lookups/day.