(uncommon) One's spouse's brother-in-law (one's spouse's sibling's husband), especially one's wife's sister's husband; either of two (or more) men who marry sisters, in relation to the other; the brother of one spouse in relation to the siblings of the other spouse.

An adage which proposes that every act has unintended consequences.

(rare, nonstandard) the grandfather of one's grandson- or granddaughter-in-law; that is, the grandfather of one spouse in relation to the grandparents of the other spouse.

(law) due process

To promulgate law. / (law, dated) To present the law that applies to a given case. / (idiomatic) To authoritatively or dogmatically assert what is permitted or not permitted.

plural of co-mother-in-law

plural of co-brother-in-law

plural of co-sibling-in-law

plural of co-sister-in-law

plural of co-grandfather-in-law