I've come across two third cousins, who are third cousins through two different routes as the same two families had two separate marriages between them that leads to this situation.

I was thinking perhaps calling them double third cousins, but would like to know the official terminology.

I've come across two third cousins, who are third cousins through two different routes as the same two families had two separate marriages between them that leads to this situation.

I was thinking perhaps calling them double third cousins, but would like to know the official terminology.

You can see an example of this relationship here. Notice that there are two sets of married ancestors, the Brown/Hodges marriage and the Brizendine/Cochran marriage, both common relations make them third cousins. See popup menu that allows navigation among the four common ancestors in this screenshot:

I've come across two third cousins, who are third cousins through two different routes as the same two families had two separate marriages between them that leads to this situation.

I was thinking perhaps calling them double third cousins, but would like to know the official terminology.

Now for DNA comparisons, I see from this table (found here: http://isogg.org/wiki/Autosomal_DNA_statistics#mediaviewer/File:Shared_cM_Project_v2_updated.png)

That third cousins would share an average of 79 cM and vary between 0–198 cM. In this case, I found 194.3 cM which seems to support the double third cousins situation, but wonder if we can be more specific as to what to expect for average and range in such a situation.

On Wikitree.com 3^rd cousins or closer is the limit to qualify for direct autosomal DNA comfirmation without requiring DNA triangulation.

Would double 3^rd cousins move one into needing triangulation or away from it to confirm the connection?

I would think it would move the relationship closer and thus be considered closer than 3^rd cousins, but with DNA it might be more complicated than that.

I've come across two third cousins, who are third cousins through two different routes as the same two families had two separate marriages between them that leads to this situation.

I was thinking perhaps calling them double third cousins, but would like to know the official terminology.