Puzzle (Kanjani Eight album) definition

(1) A toy that tests your ingenuity

(2) A particularly baffling problem that is said to have a correct solution

"He loved to solve chessmate puzzles"

"That's a real puzzler"

(3) Be a mystery or bewildering to

"This beats me!"

"Got me--I don't know the answer!"

"A vexing problem"

"This question really stuck me"

(4) Be uncertain about; think about without fully understanding or being able to decide

"We puzzled over her sudden departure"