There are a multitude of ways to express the idea of "threw a party", ranging from casual slang to more formal phrases. For instance, you might say that someone "hosted a bash", "threw a shindig", or "organized a soiree". Other options include "put on a celebration", "arranged a social gathering", or simply "threw a get-together". Depending on the setting and level of formality desired, you could also use phrases like "threw a formal reception", "held a gala event", or "put together a festive occasion". No matter which synonym you choose, it's clear that the speaker is referring to a joyous gathering of friends, family, or colleagues.