So, you know how when you eat or drink stuff sometimes it makes you feel good or happy? Well, there is a chemical called nicotine that can make some people feel that way too. But it's not good for your body, and it can even make you sick or hurt you.
A nicotinic agonist is like a pretend version of nicotine. It's a chemical that can make your body feel some of the same things that nicotine would make you feel, but without all the bad stuff. It's like pretend money - it's not real money, but you can pretend to buy things with it and feel like you have money.
Doctors sometimes use nicotinic agonists to help people who have certain health problems. For example, there are nicotinic agonists that can help people who have trouble moving their muscles. It's kind of like giving them a boost to help them move better.
But it's important to remember that nicotinic agonists are still chemicals, so they can't be used by everyone and they should only be used under a doctor's supervision. So just like you wouldn't play with real money without permission from your parents, you shouldn't take any chemicals without permission from a doctor.