The very matter that makes up everything. Content may be words on a page, pictures laid before you, or it could be pulsing, lurid, sexual content!

It is a word often used in conjunction with another, which describes what sort of content it is:

sexual content (as mentioned above)
lyrical content
verbal content

If you say it enough times in a row, it sounds really odd, and harsh, and sort of, well, stupid. Have you ever noticed how odd a word sounds if you say it enough times in a row? Try it, really, it's true.

This word is used by teachers quite often, and is usually the thing for which you receive most of your grade on an assignment.