1.
If you say that something such as a resource is ~, you mean that it is valuable and should not be wasted or used badly.
After four months in foreign parts, every hour at home was ~...
Water is becoming an increasingly ~ resource.
ADJ
2.
Precious objects and materials are worth a lot of money because they are rare.
...jewellery and ~ objects belonging to her mother.
= valuable
ADJ
3.
If something is ~ to you, you regard it as important and do not want to lose it.
Her family’s support is particularly ~ to Josie...
ADJ
4.
People sometimes use ~ to emphasize their dislike for things which other people think are important. (INFORMAL)
You don’t care about anything but yourself and your ~ face.
ADJ: ADJ n emphasis
5.
If you say that there is ~ little of something, you are emphasizing that there is very little of it, and that it would be better if there were more. Precious few has a similar meaning.
The banks have had ~ little to celebrate recently...
Precious few homebuyers will notice any reduction in their monthly repayments.
PHRASE emphasis