It's the plural of medium
This morning's New York Times on conservative activist Jon Voight:
As he spoke, his words took on more intensity, and at one point he grabbed a reporter's forearm and looked into his eyes: "If you are a patriot, get your information. You are not going to get it from the mainstream media. The media has been taken over in our country."
What do people think "media" means? The New York Times and the Tampa Bay Times and the Washington Times and the Wall Street Journal: media. Fox News and MSNBC: media. Talk radio: media. The 2016 movie: media. All those screens on that fancy stage over at the Tampa Bay Times Forum: media.