| n. | 1. | The brother of one's husband or wife; also, the husband of one's sister; sometimes, the husband of one's wife's sister. |
| Noun | 1. | brother-in-law - a brother by marriage |
BROTHER-IN-LAW, domestic relat. The brother of a wife, or the husband of a sister. There is no relationship, in the former case, between the husband and the brother-in-law, nor in the latter, between the brother and the husband of the sister; there is only affinity between them. See Vaughan's Rep. 302, 329.
in-law, relative-in-law