1.VerbTo understand; to begin to understand; to realize.
"He didn't have to explain; I caught on right away.; She's been catching on pretty well."
2.VerbTo become popular; to become commonplace; to become the standard.
"It's a crummy idea, and I certainly hope it does not catch on.; At first, many people didn't like that kind of music, but after a while it caught on."
3.VerbTo become stuck to the cooking vessel; to brown or burn slightly.