To confuse or perplex someone, making it difficult for them to understand or solve something. The complex instructions completely baffled the new employee.
To restrain or regulate the flow of a fluid, sound, or light. The engineer designed a system to baffle the noise coming from the machinery.
To defeat, foil, or frustrate the efforts, plans, or intentions of someone or something. The elaborate security measures baffled the would-be hackers at every turn.