"The spread" (noun) is a colloquial way of saying "an impressive buffet of food". For example, "you've got a nice spread here!" means "you have a wide variety of food here". "To spread" (verb) is as R. Miles said. :)

It means moving something so that it covers more area. If you spill milk, it spreads, you spread peanut butter over bread, disease spreads, responsibility can be spread among more people, and so on.

As a noun, a "spread" has several meanings, many of them in finance. Another meaning of "spread" is an expanse of land. A rancher might refer to a ranch as a "spread".

Despite the two plausible answers below, I think that you are asking about 'the spread' as it is used in sports betting. It refers to the number of points by which a team is 'favored' to win over their opponent. If team 'A' is 'favored' by 6 points over team 'B', 'the spread' is 6 points, and if you bet on team 'A', they must win by at least 7, or you lose the bet.