Just like you can with any other iOS device, you can give your watch a name of its own.

When you first set up your Apple Watch, Apple assigns a default name to it. For my watch it was “Jason’s Apple Watch.” Yours is likely something similar, only with your name, not mine.

Some people, like me, prefer to give our devices a name of our own instead of a standard affair.

To change the name assigned to your Apple Watch during setup, you only need a few seconds of your time.
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Read full post here:
https://www.cnet.com/how-to/how-to-change-the-name-of-your-apple-watch/