"Purled up" is a unique phrase that describes a specific type of physical movement, but there are several synonyms that can be used to convey a similar meaning. For example, one might say "curled up" or "coiled up" to describe the same posture. "Wrapped up" or "huddled up" could also be used to describe someone who is sitting or lying in a tight, protective position. "Nestled up" is another potential synonym that implies a sense of comfort and safety. Ultimately, the choice of words depends on the context in which the phrase is used and the specific connotations that the writer or speaker wants to convey.