Jumbo runs, consumed by mouse on ground (8)
I believe the answer is:
enormous
'jumbo' is the definition.
(thesaurus)
'runs consumed by mouse on ground' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'consumed by' means one lot of letters goes inside another (inserted letters get consumed).
'ground' indicates anagramming the letters ('grind' the letters into a new form).
'mouse'+'on'='mouseon'
'mouseon' with letters rearranged gives 'enomous'.
'r' inserted into 'enomous' is 'ENORMOUS'.
(Other definitions for enormous that I've seen before include "Colossal, huge" , "Unusually large - jumbo" , "Huge, really big" , "Massive" , "Huge, tremendous" .)