What part of speech is the new term Hashtag?

[Grassy]

Parts of speech include the following:
Noun
Pronoun
Adjective
Verb
Adverb
Preposition
Conjunction
Interjection

BQ: Could you use Hashtag in a proper sentence?

[abetterfate]

Noun.

"I added the hashtag #elephant to my tweet about my safari holiday"

[Philip]

Kill yourself

[Erik Van Thienen]

Oxford Dictionary, The American Heritage Dictionary, and Wiktionary say it's a noun.

"Spammers often broadcast tweets with popular hashtags even if the tweet has nothing to do with them."

"The hashtag #riotcleanup is being used by community members to coordinate some post-riot street-cleaning."

"Hunt mistook an @ for a hashtag while tweeting derogatory thoughts about him."

"You can also search for a hashtag by typing a topic (without the #) in the search box and clicking Search."

"While hashtags aren't formally part of Twitter, some clients, such as Tweetdeck, will persist hashtags across replies to create a sort of message threading."

"The planes are moving into position. The foreign ministers of minor Arab states are taking calls on their cell-phones from Western politicians. Twitter accounts explode around the Libyan hash-tag."

But Wiktionary says that "hashtag" can also be used on the Internet as a transitive verb, meaning 'to label (a message) with a hashtag'.

"Twitter: how to hashtag your way to fame" ( http://host.madison.com/daily-cardinal/p...f887a.html )

[Jimmy]

it's a conjunction
i hashtag that so hard