[adjective] [before noun; not gradable] [informal] [humorous] - very big or greatYou've cut me a walloping (great) slice of cake - I don't know if I'll be able to manage it.(US) Walloping can also mean very good.We had a walloping (good) time at Daryl's wedding party.
WALLOPING
Meaning of WALLOPING in English
Cambridge English vocab. Кембриджский английский словарь. 2012