The Only Use of

nominal

in

Pride and Prejudice

…and there he would continue, nominally engaged with one of the largest folios in the collection, but really talking to Mr. Bennet, with little cessation, of his house and garden at Hunsford.
p. 70.7

nominally = officially

Definitions:

(1) (nominal as in: a nominal fee)
insignificantly small
(2) (nominal as in: he's nominally in charge)
in form or name, but not in reality
(3) (meaning too rare to warrant focus)
Less commonly, in grammar, nominal means "pertaining to a noun or to a word group that functions as a noun". Even less commonly and typically in the context of space travel, nominal can mean that things are operating in a normal or expected manner--as when Andy Weir wrote "All stats nominal," in his book, The Martian.