Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† spēlaeum (spēlēum), i, n., = σπήλαιον, a cave, cavern, den (poet. and in postclass. prose; syn. antrum): in silvis, inter spelaea ferarum, * Verg. E. 10, 52; so, spelaea metuenda ferarum, Claud. B. Get. 354: emptum millibus (ab Abraham), Prud. Tetr. Vet. Test. 5: cum initiatur in spelaeo, Tert. Cor. Mil. fin.: HOC SPELEVM CONSTITVIT, Inscr. Grut. 34, 5; 34, 7; 34, 9.