Sentence:  Many husbands, like the <WSD>wives-in-law</WSD> themselves, were deeply divided and upset over a family life that could no longer be defined as a single unit. 
Meaning of the word marked with <WSD> tags:  Another wife of one's husband. Typically used in cases of divorce and subsequent remarriage for one's husband's ex-wife, but sometimes used in polygamy for a co-wife.