Nominal means existing in name only, not in reality. When something is nominal, it's technically there but so small or insignificant that it barely counts. A club might charge a nominal fee of 25 cents for membership: yes, there's a fee, but it's so tiny it's almost like being free. A country's king might have nominal power if the real decisions are made by elected officials. He has the title and the crown, but parliament actually runs things.

In science class, you might hear about nominal values, which are the stated or official measurements rather than what you actually observe. If a battery says 9 volts on the package, that's the nominal voltage, though the real voltage might be slightly different when you measure it.

When someone serves as the nominal head of a committee, they have the title, but someone else does the actual work. Being nominal isn't necessarily bad: sometimes having a small, nominal amount of something is better than having none at all, or having too much of it.