There are various synonyms for the phrase "group laugh," which refers to a moment when members of a group simultaneously burst into laughter. Some options include "collective amusement," "shared hilarity," or "unified mirth." "Collaborative chuckling," "concurrent guffawing," and "concurrent snickering" are also possible alternatives. Additionally, "simultaneous giggles," "synchronous chortling," and "coordinated laughing" all capture the concept of group members laughing together. Whether you use a traditional term like "group laugh" or opt for a more distinctive synonym, the emotion of communal amusement is one that brings people together and creates a sense of connection and rapport.