When we add fluoride ions to water, to make it good for teeth, it's called fluoridation. When we add chloride ions to water, to kill microorganisms, it's called chlorination. In the latter case, the generally used name for the process doesn't match with the technical/jargon description.
Why is this? Is it that chlorination is an older invention, so the lay word for it reflects an older technical jargon? Or is there some subtlety about the processes themselves?