Translation of "Word's" in French

What is this word's part of speech?

Quelle est la classe grammaticale de ce mot ?

- The word's origin is unknown.
- The word's origin is unclear.
- The origin of the word is unclear.
- The word's provenance is unclear.
- The word is of unclear provenance.

L'origine du mot est inconnue.

- This word's origin is unknown.
- The origin of this word is unknown.

L'origine de ce mot est inconnue.

- That word isn't in my dictionary.
- That word's not in my dictionary.

Ce mot n'est pas dans mon dictionnaire.

- I don't know this word's meaning.
- I don't know the meaning of this word.

- Je ne connais pas le sens de ce mot.
- J'ignore la signification de ce mot.