"second nature"的意思是第二天性、习性。

second nature n.第二天性,习性例句:2.It's not easy at first, but it soon becomes second nature.起初不容易，但很快就习惯了。

3. Planning ahead had always come assecond nature to her预先计划一直是她的习惯。

4. Stealing has become that rascal'ssecond nature.这家伙盗窃成性。