Number of World Series wins for each of Chicago's teams (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
three
(Other definitions for three that I've seen before include "Prime number" , "Sixth root of seven hundred and twenty nine" , "Subject of 1 9" , "... number of his "Steps to Heaven"" , "Number of blind mice" .)