Jumbo's good in shade (4)
I believe the answer is:
huge
'jumbo's' is the definition.
(thesaurus)
'good in shade' is the wordplay.
'good' becomes 'g' (abbreviation).
'in' is an insertion indicator.
'shade' becomes 'hue' (I've seen this before).
'g' placed inside 'hue' is 'HUGE'.
(Other definitions for huge that I've seen before include "Colossal" , "Extremely large" , "Enormous" , "Unusually large" , "Great in size or amount" .)