Elastic fabric (5)
'elastic fabric' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lycra that I've seen before include "Spandex" , "Synthetic fabric" , "clinging fabric" , "Sports clothes fabric" , "skin-tight garments" .)
(Another definition for stockinet that I've seen is " stretchy material".)