Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ex-creo, āre, v. exscreo.
ex-scrĕo (excr-), āre, v. a., to hawk or cough up, to spit out by coughing: per tussim exscreatur, si tolerabilis morbus est, pituita; si gravis, sanguis, Cels. 4, 6: pura, Plin. 24, 16, 92, § 145.
Absol.: age, age, usque excrea, Plaut. As. 1, 1, 27: numquam exscreare ausus, Suet. Ner. 24; Ov. H. 21, 24.