(n) :
of a man, an uncle of one's niece or nephew who is not one's brother; a co-brother-in-law as common uncle to the children of two men's married siblings.
(n) :
a man's brother, as uncle in common to the children of a third sibling
(n) :
of a man, an uncle of one's niece or nephew who is not one's brother; a co-brother-in-law as common uncle to the children of two men's married siblings.
(n) :
a man's brother, as uncle in common to the children of a third sibling