THIMBLE  , an

implement for use in sewing, serving as a protective covering for the finger in pushing the needle through the material worked upon . For ordinary purposes the thimble is a bell-shaped cap reaching to the first joint and is usually worn on the middle finger . It is made of silver or other metal; sometimes of horn, ivory or bone . The sail-maker's thimble or " thummel " is a heavy ring, worn on the thumb, with a disc attached which is the part used to press against the needle . The O.E. thymel, from which the word descends, is formed, with the suffix -el, from thuma, the thumb, the protective covering having been formerly worn on that digit . The thumb by etymology means the " thick " finger, and is to be referred to the root tum, to swell up, become thick, seen in Lat. tumere, " tumid," &c . The term " thimble " is used of many mechanical appliances, especially of various forms of sleeve, bushing or joining for the ends of pipes, or shaftings, or as covering for an axle, &c . In nautical usage the " thimble " is a metal ring concave on the outside in which a rope runs; it is a protection against chafing .