A large amount; much. — Used with "a".
Mrs. Walker's long illness cost her a good deal.
George spends a great deal of his time watching television.
- Often used like an adverb.
Cleaning up after the party took a great deal more work than the girls expected.
Usually it takes Father half an hour to drive to work, but in bad weather it takes a good deal longer.
Mother likes the gloves Mary gave her, and she uses them a good deal.
George is a good deal like his father; they both love to eat.
Contrast: A LITTLE.