Chapter 7 Changes in Word Meaning
1．Types of changes
The extension of meaning, the opposite of restriction, means the widening of a word's sense until it covers much more than what it originally conveyed.
Narrowing of meaning, also called restriction of meaning, means that a word of wide meaning acquires a narrower, specialised sense which is applicable to only one of the objects it previously denoted.
When the meaning of a word narrows toward a more favourable meaning it is called elevation
Degradation means the falling of word meaning into disrepute, for one reason or another. Words once respectable or neutral may shift to a less respectable, or even derogatory meaning.
2. Causes of changes