Spunk (noun)

1. Energy, spirit, courage, and determination.
2. Semen.

Origin:

derived from the middle english word sponk meaning "spark" or "embers".

Examples:

1. He had plenty of spunk and wasn't afraid to speak his mind.
2. She admired his spunk and determination to succeed.
3. The boxer fought with spunk and determination throughout the match.
4. It is not appropriate to use this word in a professional or polite setting, due to its second meaning.