I am going getting a GET from my wife and the Rabbi asked for my father's Hebrew name. I told him it was כלאוונא, the same as my great-grandfather. The rabbi said he had never heard of the name. After some research, we found it mentioned in the Talmud without any explanation we could understand. Can you shed any light on this? Thanks.
This appears in the Talmud in Nazir 7a. It is a combination of two word, כל meaning all or each and אוונא which means a region or section of land. It appears in a very technical discussion about taking a Nazarite vow which was given a term equivalent to a distance to another location. The term אוונא refers to a standard for measuring land.
Although it is not a common name, even in the Talmud, it is mentioned in Oholei Shem under כלאוונא where he says look at חלוונא. Looking further in Oholei Shem I can not find חלוונא. However in Kuntras Hasheimos Hachadash - note 13 & 14 he mentions a connection to Lapidus and Saadya.
The name does exist as you can see from this Lzecher Nishmas.