What is the meaning of Nb?

ISO 639-1 language code for Norwegian Bokmål.

Abbreviation of nobody.

Initialism of no ball.

Initialism of nota bene.

Alternative form of NB: initialism of non-binary.

all, every

any

lord

mistress, lady (woman with authority over something)

all, every

every other

all sorts of, all kinds of

any

Archaic in Middle Egyptian when modifying a noun.

From Middle Egyptian, this feminine singular form was generally used for the plural.
In Late Egyptian, the masculine singular form was used with all nouns.

lord, master, ruler (of a place or people)

master, superior

master (of a span of time)

owner, possessor, bearer (of an object)

possessor (of an abstract quality)

an epithet of the king

an epithet of various gods, especially Osiris

sin, damage, impurity

Alternative transliteration of nbw (gold).

Source: wiktionary.org