When you hide your profile from Discover, people you haven't connected with won't come across your profile while swiping
Your existing Connections will still be able to see you, and you will be able to continue chatting with them.
If you decide not to be shown to others on Feeld, you won't be able to see anyone on Discover, either.
To hide your profile from others on Feeld:
Go to Settings (the forth tab at the bottom).
Tap Edit Profile.
Scroll down to Show me on Feeld.
Switch off the toggle. When the toggle is grey, you'll be hidden, and when it's black, it means your profile is visible.
Remember to switch the toggle on when you feel like making new Connections again.
If you want to hide from Discover and your Connections, deactivating your account is the best option.
If you're a Majestic Member and your account is not connected to Facebook, you can turn Incognito on instead, to hide your profile from Discover to other users unless you like them first.