Lewd; obscene; pornographic; blue, dirty: He uttered a few well-chosen X-rated words
[fr the now-superseded early 1950s system of rating movies according to the amount of sex, verbal obscenity, violence, etc, they contain, X being the most censorious rating]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with xrated
Sexually explicit, vulgar, or obscene, as in This film should be X-rated; it's not suitable for children. This expression alludes to a rating system established for motion pictures, in which films rated X may not be viewed by persons under the age of 17.
[ c. 1970