Lots of (8)
(Other definitions for numerous that I've seen before include "Great in quantity" , "Legion" , "Consisting of a large but indefinite number" , "Large and indefinite in quantity" , "Great in number, many" .)
'lots of' is the definition.
(informal term for a large amount)
This is the entire clue.
(Other definitions for oodles that I've seen before include "Very many, lots" , "A lot" , "Informally, great quantities" , "masses" , "'Loads, lots (6)'" .)