Pronunciation

change

Singular
quack

Plural
quacks

  1. (uncountable) The sound made by a duck
    The duck went "quack quack".
  2. (countable) A fake or incompetent healer or doctor.
    That doctor is nothing but a lousy quack!

Plain form
quack

Third-person singular
quacks

Past tense
quacked

Past participle
quacked

Present participle
quacking

 
A quacking duck
  1. To make a noise like a duck.
    The more bread I threw on the ground, the more they quacked.
    Do you hear the ducks quacking?
    There are ducks quacking in a farm.