作祟 literally means 'to haunt (as an evil spirit)' but is more commonly used figuratively for anything that causes trouble, mischief, or negative influence — a problem, an obsession, or a hidden force. As a verb-object compound (作 + 祟), it can grammatically be separated (e.g. 作什么祟 'make what mischief'), though in practice it almost always stays together as a single unit. Note: the standard pronunciation is zuò suì (zuò for the first syllable, not zuō as the source lists).