What's the difference between delf and derf?

Delf

Definition:

• (n.) A mine; a quarry; a pit dug; a ditch.
• (n.) Same as Delftware.

Example Sentences:

• (1) I met with my conductor, Andreas Delfs , who has conducted Carmen many times.

Derf

Definition:

• (a.) Strong; powerful; fierce.

Example Sentences: