second natureBrE /ˌsekənd ˈneɪtʃə(r)/ 🔊NAmE /ˌsekənd ˈneɪtʃər/ 🔊 noun [uncountable] ~ (to sb) (to do sth) something that you do very easily and naturally, because it is part of your character or you have done it so many times 第二天性；习性