What's the difference between dreadnaught and fearnaught?

Dreadnaught

Definition:

(n.) A fearless person.
(n.) Hence: A garment made of very thick cloth, that can defend against storm and cold; also, the cloth itself; fearnaught.

Example Sentences:

Definition:

(n.) A fearless person.
(n.) A stout woolen cloth of great thickness; dreadnaught; also, a warm garment.

Example Sentences: