Other forms: mights
Might is physical strength or power. If you try with all your might to climb a difficult rock wall, it means that you try as hard as you can to get to the top.
The noun might means a person's power or strength, like the might it takes to get a stuck lid off a jar of salsa, or the impressive power of a group, like a country's military might. Might is also a verb used to express possibility, like when you might go for a walk if it doesn't rain.