spetunba lujvo

x1 is a sibling-in-law (sibling of a spouse) of x2 according to custom/law x3.

For "spouse of sibling" use "tubyspe", "bunspe" (brother's spouse), "me'ispe" (sister's spouse); for other "sibling of spouse" use "spebu'a" (brother of spouse) or "speme'i" (sister of spouse); for "sibling of one's sibling's spouse" use tubyspetunba vel sim. See also: spelanzu.


In notes:

spebu'a
x1 is a brother-in-law (brother of a spouse) of x2 according to custom/law x3.
spelanzu
x1 is the family of the spouse of x2, composed of members x3 via bonds/connections x4, where the spousal arrangement is in accord with law/custom x5.
speme'i
x1 is a sister-in-law (sister of a spouse) of x2 according to custom/law x3.
tubyspe
s1 is a brother/sister-in-law (brother's/sister's spouse) of m2 under law/custom/tradition/system/convention sp3.