Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ĭn-errans, tis, adj., not wandering, immovable, fixed; of the fixed stars: stellae eae, quae inerrantes vocantur, Cic. N. D. 2, 21, 54; 3, 20, 51; Lact. 2, 5, 18.