They had been on christian-name terms since they were children.
They were on christian-name terms, or had been a few years ago.
I was a foundling child, picked up somewhere or another, and I always understood my christian-name to be Gill.
What are you waiting for, Mr. Robber, Thief, or whatever your christian-name may be?
My husband wanted to give me a pleasant surprise, for the name of this estate is identical with my christian-name.