四大

    sìdà

    1. Nounthe four elements: earth, water, fire, and wind (Buddhism)
    2. the four freedoms: speaking out freely, airing views fully, holding great debates, and writing big-character posters, 大鸣大放 dàmíngdàfàng, 大辩论 dàbiànlùn, 大字报 dàzìbào (PRC)