1. A light, brownish, spongy preparation which burns very slowly; usually, made from fungi: "A stick of punk is used to light fireworks."
2. Decayed wood which is used when it is dry for tinder (anything that catches on fire easily): "Another term for punk is touch wood, which is a fungus that is found on old tree trunks and can be used in a stove or fireplace to keep warm."
3. Etymology: possibly from Delaware ponk, "ashes".