Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quattŭor-vĭri (quat-), ōrum, m., the board of four, i. e. a body of four men associated in certain official functions; thus, in Rome, for the superintendence of the highways, Dig. 1, 2, 2; Inscr. Orell. 773; cf. ib. 3669.
In the municipia or colonies, the board of chief magistrates, Cic. Clu. 8, 25.