'旺季' (wàng jì) literally combines '旺' (wàng), meaning 'prosperous', 'booming', or 'at its height', and '季' (jì), meaning 'season'. Together, it refers to the period of highest activity, demand, or business volume — most commonly in tourism, retail, or transportation. It implies not just popularity but measurable surges: more customers, higher prices, fuller accommodations, and longer wait times.

This term is widely used in commercial and service contexts — for example, travel agencies advertise 'off-peak' discounts by contrasting them with the 'peak season'. While often tied to calendar periods (e.g., summer holidays or Spring Festival), 旺季 can also be industry-specific: ski resorts have their 旺季 in winter, while beach destinations peak in summer. It carries a neutral-to-slightly formal register and appears frequently in news reports, official announcements, and pricing notices.