Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. fraxĭnus, i, f., an ash-tree, ash, remarkable for its slenderness: Fraxinus excelsior, Linn.
* 2. fraxĭnus, a, um, adj. [1. fraxinus], of ash-wood, ashen (usually fraxineus): virga, Ov. H. 11, 76.