1. To fit together securely, like puzzle pieces

2. The image or design that is revealed when a puzzle is completed

3. A difficult task or problem that requires thought or skill to solve

4. A game or problem that tests one's skill or knowledge

5. To finish or accomplish, like completing a puzzle

6. To swap or trade puzzle pieces with others

7. To put the puzzle pieces in a specific order or layout

8. Not present or included, like a puzzle piece that is not in place

9. To join or fit puzzle pieces together

10. Reasoning or thinking skills used to solve puzzles

11. A single part of a whole puzzle

11. Characterized by being broken into separate puzzle pieces

12. A type of puzzle that is completed by fitting together interlocking pieces

13. An activity or competition involving puzzles or problem-solving

14. The outermost part of a puzzle, often with a straight border

15. The right-angle part of a puzzle, usually found at the edges

16. To find the solution or answer to a puzzle

17. To turn or spin a puzzle piece to a different position

18. To match or go well together, like puzzle pieces

19. The physical form of a puzzle piece