WordNet
double digit
n. a two-digit integer; from 10 to 99
Usage examples of "double digit".
Mom hit the road shortly after she was born, hightailing it to parts unknown with a Schlitz Brewery driver rumored to be double digit hung, like the human equivalent of Mickey Cohen, Jr.
That witness had the impression that the car bore Florida plates but had a single digit before the hyphen rather than the double digit designating Courtney County.
I guess for true privacy you did need less than a double digit worth of people in a room.