Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cŏāgŭlo, āvi, ātum (contr. COAGLAVI, Inscr. ap. Anthol. Lat. 1177 Meyer), 1, v. a. [coagulum], to cause a fluid to curdle or coagulate (mostly in the elder Pliny): lac, Plin. 12, 25, 54, § 123; 20, 14, 53, § 147: picem, id. 16, 11, 22, § 53; v. Sillig N. cr.: aquam, id. 20, 23, 97, § 259: sudorem, id. 35, 15, 52, § 186: caseum, Pall. Mai, 9, 1 al.