UPDATE July 7, 2015: The answer to the CMOS Challenge is that vice-president is not Chicago style. CMOS spells this term without a hyphen: vice president. You can learn more about Chicago-style hyphenation at section 7.85 of The Chicago Manual of Style (our famous “Hyphenation Table”). And in case you’re curious, here’s how you voted:

vice-president 70%
megamall        17%
three-year-old 9%
self-restraint   4%