> the use of a word to include something "like" but not "the same".
Let me add two examples with well known words concerning plants. Such
shifts are quite common with all kinds of words: a use of a word that
starts as "wrong" or "confused" becomes the norm.
There's the good, ancient word, _corn_ in "Anglo-Germanic," that has
meant the usual European crops in European languages for perhaps 4,000
years (the same ancient word resulted in the Slovak _zrno_ with the
same meaning, in the Latin _granum_, etc.). And yet, when the Anglos
arrived in America, they abandoned its well-established meaning and
applied the ancient word _corn_ to a single new plant they'd never
The word _marmalade_ is based on the word that gave the English
_melon_ (and used to mean "quince"), not _orange_.