What does capsaicin mean in cooking?

capsaicin means: This compound is found in chili’s placental ribs. The heat from chili causes watery eyes and a runny nose. It also contributes to burning sensations such as sweating, running nose, headaches, and even nausea. The ability to not only stimulate the pain receptors of your digestive tract but also to block them has been proven. This allows you to get used to eating hotter, hotter foods. (in Cooking Dictionary)

What else does capsaicin mean?

• A colorless, pungent, crystalline compound, C ₁₈ H ₂₇ No ₃ It is made from some capsicums, and can cause severe irritation to the skin and mucous membranes. (in Merlin Dictionary)