Definitions for "dipped"
a term for a coin that has been placed in a mild acid wash solution to remove toning
A coin which has been cleaned in a soap solution, the most popular of which is called "Jewel Luster"(c), is said to have been dipped. The term "dipped" is not considered necessary in, say, a catalog description of a coin, unless the dipping has caused noticeable dulling of lustre, or an otherwise unnatural appearance (usually on copper coins). The practice of dipping coins is not advisable, except by bonafide experts, and even then only on rare occasions.
(dipping, dip) - a coin that has been treated with chemical solution to enhance its appearance. Solutions are often a form of diluted acid.
having an abnormal sagging of the spine, especially in horses.