What do you call this familial relationship?

Oh, I agree that “your mother’s sister’s husband” is included in the English definition of “uncle”.

I came across that recently and did not believe that was correct. Again, I have no problem with people using whatever terms they want; it is their life. But I had the belief that only your first two definitions were correct.

Words mean what people use them to mean. Some people interpret the term “sibling-in-law” the way @lobotomyboy63 does; some interpret it the other way. I’m not sure which is more common.

And some people aren’t even sure of how they interpret it:

Upon reflection, maybe the third def is needed. If my wife’s sister is my SiL and that woman’s children are my nephews/nieces by marriage, it wouldn’t be very welcoming not to include her husband. At the mention of " -in laws," someone studying genetics stops listening…there’s nothing to consider.

My family has a few double cousins sprinkled here and there. In line with that, I’d vote for calling the boys double-half-brothers.

3/4-brother would work, but would sound like you’re trying to be precise. With double-half-brothers, you sound like you don’t care whether anyone gets it of not.

I like “double-half brother.”

I have double second cousins and first half cousins: or are they half first cousins? In theory the two groups share the same about of genetic material with me (6.25% according to https://isogg.org/wiki/Autosomal_DNA_statistics).

Okay, all y’all, what do you call this relation?

Father of Putin’s goddaughter captured in Ukraine: Zelenskyy

step-god-brother-in-law?

(It can’t be god-father-in-law. That would be the in-law of your own god-father, or the god-father of your own in-law.)

If Putin is the god-daughter’s god-father and that god-daughter has a father, then Putin and the god-daughter’s father some kind of brothers, right? They are some kind of step-brothers. They are some kind of god-inlaws. So, step-god-brothers-in-law.