Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
†† cŏvīnus (cŏvinn-), i, m. [Celtic], a war-chariot of the Britons and Belgæ, Mel. 3, 6, 5; Luc. 1, 426; Sil. 17, 422.
Also a travelling chariot, a kind of tilbury, Mart. 12, 24, 1.