Your cousin-in-law.
sisters in law
She is your sister-in-law.
cousins
Our cousins are our mothers sisters son :)
Brother-in-law.
your brother-in-law :)
Your sister-in-law.
If his great grandmother and your grandmother are firstcousins, the you and he are third cousins, once removed.
Phillipp uncle
by his given name of course.. or cousin
There is no specific word for the husband of your wife's sister. If you need a phrase, call him your "sister-in-law's husband."