Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. ărānĕus, i, m. [ἀραχνός]. 
- I.  A spider, Lucr. 3, 383; Cat. 23, 2: aranei (apibus) hostiles, Plin. 11, 19, 21, § 65: araneorum natura, id. 11, 24, 28, § 79: aranei textura, Sen. Ep. 121, 22 al.
- II.  A sea-fish: Draco trachinus, Linn.; Plin. 32, 11, 53, § 145.
2. ărānĕus, a, um, adj. [1. araneus]. 
- I. 
- A.  Pertaining to the spider, spider’s-: genus, Plin. 18, 17, 44, § 156: texta, id. 29, 4, 27, § 86.
 Hence,
- B.  Subst.: ărā-nĕum, i, n., a spider’s web,  =  ἀράχνιον: tollere haec aranea quantum est laboris? Phaedr. 2, 8, 23.
- 2.  A disease of the vine and of the olive-tree, Plin. 17, 24, 36, § 7.
 
 
- II.  Araneus mus, a kind of small mouse, acc. to some the shrew-mouse, Col. 6, 17, 1; Plin. 8, 58, 83, § 227.