The phrase "sit for" has a variety of synonyms depending on the context. In terms of an exam or test, "take" is often used instead of "sit for." "Participate in" or "attend" can also be used as synonyms in this sense. If referring to a portrait being painted or a photograph being taken, "pose for" can be used. "Await" or "expect" can be used if waiting for an opportunity to arise, while "endure" can be used in a negative context, such as "I cannot sit for this any longer." Overall, the synonyms for "sit for" depend on the intended meaning and context of the phrase.