(historical) The four traditional things targeted for destruction during China's Cultural Revolution, usually translated as old customs, old culture, old habits, and old ideas.

(organic chemistry) The glucosinolate [(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl] 4-methylsulfonyl-N-sulfooxybutanimidothioate

Something which envelops

Misspelling of are.