(pĕr'ĭ-trĭk') n., pl., pe·rit·richs, also pe·rit·ri·cha (pə-rĭt'rĭ-kə). Any of various protozoans, such as the vorticella, having a wide oral opening surrounded by cilia.
[From New Latin Peritrichida, former order name : PERI- + Greek thrix, trikh-, hair.]