which has different meanings.
A catchy song is one you easily remember.
A catchy idea is a very attractive or appealing one.
A catchy question is a tricky or difficult question.
This word obviously derives from the verb "to catch" and so it means easily retained (caught) in the memory, tending to catch the interest or attention (attractive, appealing), or a question which catches you because it's tricky or difficult.
The new slogan isn't as catchy as the old one.
The chorus of that song is so catchy. I can't get it out of my mind.
Now it's your turn. Write a comment with an example.