Nominal

Nom"i*nal (?), a. [L. nominalis, fr. nomen, nominis, name. See Name.] 1. Of or pertaining to a name or names; having to do with the literal meaning of a word; verbal; as, a nominal definition. Bp. Pearson.

2. Existing in name only; not real; as, a nominal difference. "Nominal attendance on lectures." Macaulay.

Nom"i*nal, n. 1. A nominalist. [Obs.] Camden.

2. (Gram.) A verb formed from a noun.

3. A name; an appellation.

A is the nominal of the sixth note in the natural diatonic scale.
Moore (Encyc. of Music. )