What's the difference between quean and quern?

Quean

Definition:

• (n.) A woman; a young or unmarried woman; a girl.
• (n.) A low woman; a wench; a slut.

Example Sentences:

Quern

Definition:

• (n.) A mill for grinding grain, the upper stone of which was turned by hand; -- used before the invention of windmills and watermills.

Example Sentences: