If you deactivate your profile, you won't appear in Discover and your Connections will not be able to see your profile or message you
However, your account will not be terminated and you'll be able to return to it in the future.
To deactivate your account:
Go to 'Settings'.
Tap 'App Settings'.
Scroll down to 'Deactivate'.
Please note that your Connections will be able to disconnect from you.
If you just want to disappear from Discover while remaining accessible to your Connections, you can hide your profile instead.