Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cursūra, ae, f. [curro], a running (ante-class.), Plaut. Bacch. 1, 1, 34; id. Merc. 1, 2, 10; id. As. 2, 2, 61; id. Most. 4, 1, 5; id. Trin. 4, 2, 164; Varr. R. R. 2, 7, 15 al.