No, what does it mean?
It's Latin for "deposit of faith," and refers to the teachings handed down from the times of the Apostles. The canonical books of the Bible are part of that deposit, as are the official dogmas of the Catholic church. The Catholic church's moral teachings on sexuality, as defined in the New Testament and Tradition, are part of that deposit. The Catholic church's entire claim to authority is based upon its being entrusted with preserving and handing down that tradition. In short, if the Catholic church were to ever change the "depositum fidei," it would be undermining its entire claim to be the One, Holy, Catholic and Apostolic church. I doubt that will ever happen (and hold as a matter of faith that it will not, since Christ promised that "the gates of Hell shall not prevail").