My brother's father-in-law is my what?

Factual Questions
41

Ancient Latin had very precise terms for relationships between family members. Many languages do (although I don’t think any are as specific as the imagined one in Heinlein’s Citizen of the Galaxy). My Latin dictionary has an interesting page showing these terms in a family tree, but I don’t have it here, and haven’t been able to find anything similar in a quick internet search. I’ll bet they had a term ffor what the OP is looking for.

Contemporary English is sadly deficient in such terms. We end up labeling a lot of folks “cousins” of various sorts, or “great aunts/uncles”.

42

Thanks! I crave an OED, but can’t quite justify buying it.

43

Cal, I think I found what you were looking for - is this it?

Latin Family Relationship Titles

44

Basically. I think the one I saw went a little farther, and had it all in one diagram, but that’s the basic idea.

45

What I want is a term for what my sons’ in-laws (especially M&FIL) are to me (other than competition). Because I think that’s a relationship unlike others.

I’ve been tempted to use Shecky’s out-laws, and not because of any animosity.

46

My mother referred to such people as “Christmas Card Cousins” as that was the only time of the year they came anywhere near her radar screen.