The plane mistaken for jumbo (8)
I believe the answer is:
'jumbo' is the definition.
(I've seen this before)
'the plane mistaken' is the wordplay.
'mistaken' is an anagram indicator.
'theplane' with letters rearranged gives 'ELEPHANT'.
'for' is the link.
(Other definitions for elephant that I've seen before include "Then leap (anag.)", "Pachyderm hunted for ivory", "Large animal found in the plane?", "Get this animal from Pat and Helen", "Largest land mammal".)