sister-out-law

Japanese Meaning

恋人の姉妹 / 兄弟姉妹の彼女 / 元配偶者の姉妹

At first I felt awkward meeting my sister-out-law, but we discovered we liked the same books.

最初は恋人の姉に会うのが気まずかったけれど、同じ本が好きだと分かって仲良くなりました。

Sense（1）

The sister of one's boyfriend or girlfriend.

Sense（2）

Girlfriend of one's brother or sister.

I, on the other side, was ready to strangle my almost sister-in-law. (My sister out-law.)

Sense（3）

The sister of one's ex-spouse.

sisters-out-law

（ plural ）