Okay, the user wants me to translate "shake head" into Thai. Let me think. The direct translation of "shake head" in Thai is "สั่นหัว" (sān hūa). But wait, is there a more common or idiomatic way to say it? Sometimes, depending on context, there might be different expressions. For example, if it's a command or a gesture, maybe "สั่นหัว" is correct. Let me check a dictionary or some examples. Yes, "สั่นหัว" is the standard translation. The user specified to translate all content into Thai unless it's already in Thai. Since "shake head" is in English, I need to translate it. Also, the user wants only the translation without any explanations. So I should just output "สั่นหัว" without any extra text. Make sure there are no typos. Alright, that should be it.