To count is to calculate how many or how much of something there is. A first grade teacher might stop and count her students before they board a bus after a field trip.
You can count your money, adding up the dollars and quarters, or count the calories in the food you eat each day. When your cat has kittens, you might count them and announce, "Seven kittens!" Another way to count is to list the numbers in order: "One, two, three, four..." When count is a noun, it refers to the title of a nobleman. This meaning comes from the Latin comes, "companion," or specifically "companion to the emperor."