Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
suppūrātĭo (subp-), ōnis, f. [suppuro], a purulent gathering, an imposthume or abscess, a suppuration, Cels. 2, 8; 3, 27 fin.; 7, 2 fin. al.; Plin. 20, 3, 8, § 16; 23, 1, 16, § 24; 24, 4, 7, § 13; Col. 6, 12, 4; 6, 38, 2; Sen. Ep. 14, 1, 5.