遊離基: (chemistry) free radical

study of something; the sum of knowledge accrued by scholars; the realm of refined learning; scholarship

hanging something up (tying to a high place) / kangaroo court (an unjust (quasi-)judicial proceeding or group)

(archaic, of sky or ocean) blue / (archaic, of vegetation) dark green; luxuriantly green / (archaic) dim, gloomy