[arrrg]

Here’s the Oxford English Dictionary (funny how words work – I know of all five those meanings of nominal, but when I hear it I first think of the fifth, while you first seem to think of the first three):

nominal |ˈnɒmɪn(ə)l|

adjective

1 (of a role or status) existing in name only: Thailand retained nominal independence under Japanese military occupation.

• relating to or consisting of names.

2 (of a price or charge) very small; far below the real value or cost: they charge a nominal fee for the service.

3 (of a quantity or dimension) stated or expressed but not necessarily corresponding exactly to the real value: EU legislation allowed variation around the nominal weight (that printed on each packet).

• Economics expressed in terms of current prices or figures, without making allowance for changes over time: the nominal exchange rate.

4 Grammar relating to or functioning as a noun: a nominal group.

5 informal (chiefly in the context of space travel) functioning normally or acceptably.