The word pitch has several meanings:

1. To throw something, especially a baseball. A pitcher pitches the ball toward home plate, trying to make it difficult for the batter to hit. You might also pitch a tent when camping, setting it up by driving stakes into the ground, or pitch hay with a pitchfork on a farm.
2. To present an idea to try to convince someone. When you pitch an idea for a class project, you're explaining it in a way that makes others want to support it. Business owners pitch their ideas to investors, hoping to get funding. In this way, pitch can also be used as a noun: “The entrepreneur delivered a great pitch for her business.”
3. The highness or lowness of a sound. A piccolo plays at a high pitch, while a tuba plays at a low pitch. When someone's voice rises in pitch, it gets higher and squeakier. Musicians tune their instruments to match the right pitch.
4. A thick, dark, sticky substance made from tar. Ships were once sealed with pitch to make them waterproof. This meaning also appears in the phrase pitch-black, describing darkness as deep as this black substance.