Colon (noun)

1. The main part of the large intestine, which passes from the cecum to the rectum and absorbs water and electrolytes from food that has remained undigested.
2. A punctuation mark (:) used to precede a list of items, a quotation, or an expansion or explanation.

Origin:

From latin colon ('part of the large intestine').

Examples:

1. The colon is an important organ in the digestive system.
2. In English, the colon is used to introduce a list of items.
3. The colon can also be used to introduce a quotation.