What part of speech is the word multitude?

Multitude is a noun which means (1) a huge number, (2) the masses or the populace, and/or (3) the condition or quality of being numerous.

The class had a multitude of questions when the essay contest was announced.

There are a multitude of sentences you could come up with using the term multitude.

A famous quote using the Word is:

"The respect of those you respect is worth more than the applause of the multitude." (Arnold H. Glasow)