My word is "dynamite" which has two meanings. 1)n. a powerful explosive made by soaking nitroglycerin in some absorbent, such as ammonium nitrate and wood pulp. 2)adj. outstanding, very exciting.

My question is - name the part of speech given in the first entry.

1)n. a powerful explosive made by soaking nitroglycerin in some absorbent, such as ammonium nitrate and wood pulp.

What does n. stand for in that definition?

The part of speech given in the first entry of "dynamite" is a noun (abbreviated as 'n.').

To determine the part of speech of a word, you can consult various resources such as dictionaries. Most dictionaries provide the part of speech information for each word entry. In this case, you have correctly identified that the first entry for "dynamite" corresponds to the noun form of the word.