In dictionary entries, the letter n means

noun.
next.
new.
none.

noun.

Explanation:

In dictionary entries, there are abbreviations, in the case of n. (noun), that function as indicators of the different parts of speech of the English language (verb tense, grammar) the words defined belong.

Other abbreviations are used to indicate different subjects such as the origin of words, L. (latin); or the use of a word in specific circumstances, colloq. (colloquial).

Other examples of abbreviations are:

jessica, a teenage girl who just wants popularity, does everything to get attention. she puts her hair in a bun and steals her mom's lipstick and such. but then she takes something and it makes her inside and outside appearance  go bad.

i just came up with that in less than 60 seconds, but tweak it up if you like it.

explanation:

you didn't give a theme but i did a question like this a while ago so i hope this is what you were looking for.

the answer is the second one.