Is meeting a possessive

No, the Word 'meeting' is a singular, common, abstract noun; a Word for an assembly or gathering of people.

A possessive noun is a noun indicating ownership or possession.

Possessives are formed by adding an apostrophe -s to the end of the Word, or just an apostrophe to plural nouns that already end with -s. For example:

noun: The meeting will be held at four.

possessive noun: The meeting's agenda will be sent to you by email.