Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Mentor, ŏris, m.,  =  Μέντωρ. 
- I.  The famous friend of Odysseus, Cic. Att. 9, 8, 2. 
 
- II.  A celebrated artist in embossed work in metal, Cic. Verr. 2, 4, 18, § 38; Plin. 33, 12, 53, § 147.
 
- B.  Poet. transf., a Mentor-cup, a skilfully wrought drinking-vessel: rarae sine Mentore mensae, Juv. 8, 104: Mentora frangere, Mart. 11, 11, 5.
Hence, Mentŏrĕus, a, um, adj., of or belonging to Mentor the artist, Mentorean: opus, Prop. 1, 14, 2: labores, Mart. 4, 39, 5.