It has a specific meaning in a specific environment, the meaning of double quotation marks. . .
Hey, Blair, how about going shopping on Saturday?
Blair: Well, I'm afraid I can't. I must study in the library on Saturday.
Serena: Ha ha ha, you said you were going to study in the library. I know when you say study, you mean kissing Nate. I'm afraid the library is Nate's room