διαθήκη/diathēkē

This word is a type of thing or idea. It is a noun.

This word can mean a will or testament. This is the plan a person makes before he dies. He says who will receive his property after he dies.
This word can mean a covenant. This is an agreement or plan made between two people to do something.
- Sometimes it is used to talk about a very serious agreement between two people. The two people promise to do something for the other person.
- Sometimes it is used to talk about the words that people speak or write when they make a serious plan or agreement.