No this isn't possible. If you want to use two words, you either have to put them together or use a hyphen or underscore.
There are a number of characters that you can't use either. Not sure what the list is, but if you try to use them you get an error and all the labels you had been entering disappear.
We do have following improvement request. You can see the list of the characters that you can't use in the label in this ticket:
I'd recommend you to watch and vote for this request and check Implementation of New Features Policy to see how Atlassian chooses what to implement.
More and more people are building their careers with Atlassian, and we want you to be at the front of this wave! Important Dates Start the Certification Prep Course by 2 April 2019 Take your e...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs