Semantic change
Evolution of a word's meaning
Semantic change (also semantic shift, semantic progression, semantic development, or semantic drift) is a form of language change regarding the evolution of word usage—usually to the point that the modern meaning is radically different from the original usage. In diachronic (or historical) linguistics, semantic change is a change in one of the meanings of a word. Every word has a variety of senses and connotations, which can be added, removed, or altered over time, often to the extent that cognates across space and time have very different meanings.
From Wikipedia, under CC BY-SA. More on occurri.