1. To place the hand, finger, etc., in contact with. 14. To affect the emotions of; move, especially to pity, gratitude, sympathy, etc. -- Funk & Wagnalls Canadian College Dictionary
So, touching an object to get a sound became toccare, which became touchier, which became touch. And then it's only through the wonders of human communication and time that the current 106 related meanings (that I could find) came into use in English. Here are a few of them:
- get in touch -- make contact with someone
- soft touch -- a person who is easily manipulated. This term is first recorded in 1940.
- touch -- to stir emotionally. First used in the mid-1300s.
- touch -- to feel with the hand or other body part, from the late 1200s
- touche -- an exclamation that comes from fencing, 1904. Has also come into general use to mean someone scored an emotional or intellectual point.
- touched -- stirred emotionally, since the mid-1300s
- touching -- affecting the emotions, from 1601
- touch off -- usually means to set off an argument or sensitive feelings
- touchy -- too sensitive, from 1605. This is probably an alternate form of "tetchy," which means the same thing.