Do you mean while introducing them to other people or mentioning them in conversation? I suppose you could just refer to them as (name), your partner or just the latter, depending on the situation.
Typically, I've seen them referenced as enbyfriend. I haven't dated sonve I came out to most people, so I haven't had to really wordy about that yet.
It'll be good to ask them. If you're not sure, you can call them your "partner" if they're okay with it.