Select the most appropriate meaning of the given idiom.

Of the first water

of the best quality

The most appropriate meaning of the idiom "of the first water" is >of the best quality.<

This idiom is derived from the grading system for diamonds, which used to be based on their clarity and color. A diamond of the first water was considered to be the best quality, with no flaws or blemishes.

The idiom is now used more generally to describe something that is of the highest quality or standard. For example, you might say that a painting is of the first water if it is a masterpiece.

The other options are not correct.

• Of ancient origin: This does not mean the same thing as of the best quality.
• Of favorable opinion: This means that someone has a good opinion of something.
• Of no significance: This means that something is not important or meaningful.