(~s, ~ing, ~ed)
1.
If you call someone a ~ or a ~ doctor, you mean that they claim to be skilled in medicine but are not.
I went everywhere for treatment, tried all sorts of ~s.
N-COUNT: oft N n disapproval
2.
Quack remedies or ~ cures are medical treatments that you think are unlikely to work because they are not scientific.
ADJ: ADJ n disapproval
3.
When a duck ~s, it makes the noise that ducks typically make.
There were ducks ~ing on the lawn.
VERB: V
•
Quack is also a noun.
Suddenly he heard a ~.
N-COUNT; SOUND