Harm
Harm is a type of token that is added to cards by tests and other effects. What it represents varies considerably from card to card. On beings it may represent physical harm, but it can also represent distress. On features it may represent how much damage a physical object can suffer before it breaks, or the process of hacking a path through the brush. It can also be a measure of how much material can be harvested from a plant before nothing of use remains.
Your instinct may be to think of a card’s harm threshold as its “hit points,” that is, the amount of damage it can sustain before it is killed or destroyed, but that it not necessarily the case. You clear a card with harm when the amount of harm equals or exceeds its harm threshold. This means you've simply done enough damage or caused enough distress to cause it to flee. When you clear a feature from harm, you’ve overcome it through force or have depleted it of its resources.