The pitch of something is the level of something, such as a level of activity or emotion. A fever pitch is a state of activity or excitement that is extreme.
The symphony members enjoyed the speed of the difficult piece of music, as the song concluded only after a fever pitch of notes and percussion amazed the audience.
The nervous father to be had worked himself into a fever pitch on the way to to the hospital after getting the news that his wife was in labor.
Pitch is also used in the phrase in pitch darkness. When you are in pitch darkness, you are unable to see, since there is little to no light.
The surprise storm left the city in pitch darkness, with people stuck in their homes until the morning light finally arrived.
When I am going to stay late at work, I always ask our caretakers to leave the lobby lights on so I am not walking out into pitch darkness.
Repentant describes a person who feels regret for his words or actions. It is a strong type of regret, and one might take some action to make up for wrongdoings. To repent means to take some action that demonstrates that one regrets something he has done.
Repenting is not something one does casually, because it requires a strong mind to change one's ways permanently.
Repentant often has an association with religion. In the Catholic Church, confession is often followed by some sort of action assigned by the priest. In this case, the repentant individual is also known as a penitent.
Your mother may make you do housework as a penance for staying out past your curfew. Next time you should arrive on time.
A true penitent spends the rest of his life refraining from committing the misdeed that originally led to his serving a penance.