What is the term for words that have changed meaning over time?

What is the term for words that have changed meaning over time? For example, in relation to this question on Workplace Stack Exchange the term snafu was of military origin and was used to define a person, team, organisation, etc that continually makes mistakes. The first time I saw the term was in relation to a data protection leak and this now seems a pretty common usage e.g this article amongst the tech community.

Is there a term to describe words that have changed meaning over time, or words that have been adopted by a particular community and had their meaning altered?

Solution 1:

There isn't a word for those words, but the evolution of meaning is called semantic change.

Solution 2:

Snafu has not so much changed its meaning over time as come to be used by a larger linguistic community. Nevertheless, words do change their meaning over time. Where a word with a general meaning comes to have a more specific one, the process is semantic narrowing. An example is deer, which once meant any kind of animal, but now means only members of the family Cervidae. The opposite process is semantic widening. An example is office, which was limited to various ecclesiastical meanings before developing the uses which we know today.

Solution 3:

At first I thought this...

anachronisms (words which have changed in meaning over the centuries)

...was a slightly odd definition. But then I realised I was conflating anachronisms with archaisms (words which aren't used at all any more). In a language context, an anachronism arises if you try to use a word with a meaning which it no longer has (because the meaning has changed).