In English language, there are numerous synonyms for the phrase "sitting in". Some of the common synonyms include "occupying" which means to take control of a space or area, "inhabiting" which implies living or occupying an area, "perched" which suggests sitting in a position of elevated height, "resting" which refers to sitting calmly and peacefully, and "seated" which indicates sitting down in a specific spot. Additionally, other synonyms of "sitting in" include "parked", "waiting", "lounging", "settled" and "ensconced". Each of these synonyms has a different connotation and use, and it is essential to understand their meanings in the context they are being used.