To puzzle over something is to think hard about what you cannot make sense of. Puzzle over the handwriting, puzzle over the accounts.
It implies effort without progress, which is what separates it from working something out. It takes over rather than about, and the thing puzzled over is usually small and specific.
1phrasepuzzle overTo think hard about something you cannot make sense of.
“They puzzle over the same two lines every year.”
puzzle over is a phrase.
Practised in Thinking & Memory