돌팔이 의사

quack(noun)

(used as an adjective) a person who dishonestly claims to have medical qualifications

a quack doctor/psychologist; quack medicine/cures.

(집오리 등의) 꽥꽥 우는 소리

quack(noun)

the cry of a duck.

꽥꽥 울다

quack(verb)

to make such a sound

The ducks quacked noisily as they swam across the pond.