四大

sìdà
  1. the 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, 大鳴大放 dàmíngdàfàng, 大辯論 dàbiànlùn, 大字報 dàzìbào (PRC)

CEDICT

buddhism

Entry Composition

1 四 sì
  1. four
  2. 4
2 大 dà
  1. big; large; great
  2. older (than another person)
  3. eldest (as in 大姐 dàjiě)
  4. greatly; freely; fully
  5. (dialect) father
  6. (dialect) uncle (father's brother)