Emily Dickinson Lexicon

CO'LON, n. [Gr. κωλον, the colon, a member or limb.]

1. In anatomy, the largest of the intestines, or rather the largest division of the intestinal canal; beginning at the cæcum, and ascending by the right kidney, it passes under the hollow part of the liver, and the bottom of the stomach, to the spleen; thence descending by the left kidney, it passes in the form of an S, to the upper part of the os sacrum, where, from its straight course, the canal takes the name of rectum. – Encyc. Quincy.
2. In grammar, a point or character formed thus [:], used to mark a pause, greater than that of a semicolon, but less than that of a period; or rather it is used when the sense of the division of a period is complete, so as to admit a full point; but something is added by way of illustration, or the description is continued by an additional remark, without a necessary dependence on the foregoing members of the sentence. Thus, A brute arrives at a point of perfection he can never pass: in a few years he has all the endowments he is capable of. – Spect. No. iii. The colon is often used before an address, quotation or example. “Mr. Grey was followed by Mr. Erskine, who spoke thus: 'I rise to second the motion of my honorable friend.'” But the propriety of this depends on the pause, and this depends on the form of introducing the quotation; for, after say, said, or a like word, the colon is not used, and seems to be improper. Thus, in our version of the Scriptures, such members are almost invariably followed by a comma. “But Jesus said to them, 'Ye know not what ye ask.'” The use of the colon is not uniform; nor is it easily defined and reduced to rules. Indeed, the use of it might be dispensed with without much inconvenience.