Material carried by wobbly crate (5)
I believe the answer is:
lycra
'material' is the definition.
(I've seen this before)
'carried by wobbly crate' is the wordplay.
'carried by' indicates the answer is hidden within the clue.
'LYCRA' is hidden in the letters of 'wobbly crate'.
(Other definitions for lycra that I've seen before include "Sportswear fabric" , "Stretchy sports material" , "Spandex" , "gear for cyclists" , "Stretch fibre" .)