pseudomyxoma peritonei pseudomyxoma per·i·to·ne·i (pěr'ĭ-tn-ē'ī)
n.
The accumulation of mucoid or mucinous material in the peritoneal cavity, either as a result of rupture of a mucocele of the appendix or of rupture of a benign or malignant cystic neoplasm of the ovary.