courage noun

Synonyms: courage, bravery, nerve, guts
Antonym: cowardice

Synonyms:
courage: the ability to deal with a dangerous or unpleasant situation
Example: She showed great courage in attacking the burglar. I didn’t have the
courage to disagree with him.

bravery: the ability to do dangerous or unpleasant things without being afraid
Example:  We admired her bravery in coping with the illness. He won an award for bravery.

nerve: the ability to keep your fear under control in order to achieve something
Example: It takes a lot of nerve to disagree with your friends.  He went over to speak to her but at the last minute he lost his nerve.

guts: (informal) courage
Example: She had the guts to tell the boss he was wrong.

Antonym:
cowardice: the state of being afraid and not brave