Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prae-fōco, āvi, ātum, 1, v. a. [faux], to choke, strangle, suffocate (poet. and postclass. for suffoco): animae viam, Ov. Ib. 560: partum, Dig. 25, 3, 4: Jovem, Arn. 7, 29: messis praefocata, Calp. Ecl. 4, 115: ex abundantiā praefocari, Macr. Somn. Scip. 1, 12.