Roysterer is a term that refers to someone who is boisterous and enjoys lively and noisy revelry or parties. There are many synonyms for this word, including carouser, partygoer, reveler, merrymaker, and reveller. Other synonyms for roysterer include jolly-maker, racketeer, and bacchanal. These words all describe someone who enjoys a good time with friends, often involving music, dancing, and drinking. It's important to note that while these words all have similar meanings to roysterer, they may have slightly different connotations or nuances. Regardless, they all express a sense of enthusiasm and excitement for socializing and having fun.