Which part of speech is the word justice?

"Justice" is a noun.

Explanation:

A noun is a person, place, thing, or idea. "Justice" is an idea (or a person, depending on the context). You might say, "the criminals were attempting to escape justice", for example. In this sentence, justice is an idea that represents the administration of the law, making it a noun.

Furthermore, it is not an adjective because it does not describe something. It is not a verb because you cannot be "justicing". It is not an adverb because it does not modify another word. It is not a pronoun because it does not refer to another noun. It is not a preposition because it does not describe the position or general manner of another word. It is not a conjunction because it cannot be used to join two phrases together. Lastly, it is not an interjection because it is not used to express a strong feeling or a sudden emotion.