Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
2. pŏtĭo, īvi, īre, v. a. [potis], to put into the power of, to subject to any one: eum nunc potivit pater Servitutis, made a slave of him, reduced him to slavery, Plaut. Am. 1, 1, 23: potitu’st hostium, fallen into the enemy’s hands, id. Capt. 1, 1, 24; 1, 2, 41; 3, 5, 104; cf. id. Ep. 4, 1, 5; 4, 1, 35; Paul. ex Fest. p. 250 Müll.