Talk:half sister-in-law
Definitions 4 and 5 seem quite odd at first reading.
The possible permutations I can see for a half-sister-in-law are:
A. The half-sister of someone's husband. (The current definition #1)
B. The half-sister of someone's wife. (The current definition #2)
C. The (opposite-sex) wife of someone's half-brother. (The current definition #3)
D. The (same-sex) wife of someone's half-sister. (This possible definition is not included, possibly intentionally)
E. The (same-sex) wife of the half sister of someone's husband. (This is the meaning, even if unintentional, of the current definition #4)
F. The (same-sex) wife of the half sister of someone's wife. (This is the meaning, even if unintentional, of the current definition #5)
G. The (opposite-sex) wife of the half brother of someone's husband. (This definition is not included, however, I suspect this was originally intended to be the meaning of definition #4)
H. The (opposite-sex) wife of the half brother of someone's wife. (This definition is not included, however, I suspect this was originally intended to be the meaning of definition #5)
This isn't the place to debate the legitimacy of same-sex spousal arrangements, and personally I wouldn't want to dispute them the first place. However, I would argue that all the definitions could be reduced as follows:
1. The half-sister of someone's spouse. (Covers current definitions 1 and 2)
2. The wife of someone's half-sibling. (Covers current definition 3, as well as the omitted possible definition D)
3. The wife of the half-sibling of someone's spouse. (Covers current definitions 4 and 5, as well as the omitted possible definitions G and H)