They are connected by marriage.

他们已联姻。

《牛津词典》

"Connected by marriage, you mean," said Franz, laughingly.

“婚姻关系吗？”弗兰兹大笑着说。

youdao

I met her just once, and she's only a second cousin by marriage.

事实上，我只和她见了一面，而她只是一个远房亲戚。

youdao

By the end of the play, love wins over everyone and there is a marriage ceremony for the four lovers.

VOA: special.2010.01.06

Professor John Rogers: Milton is typically cited by literary historians as one of the first major English poets to praise in verse the institution of marriage.

约翰·罗格斯教授：文学家们说弥尔顿,是英国早期诗人中,赞美婚姻制度的一员。

耶鲁公开课 - 弥尔顿课程节选

A survey last April by the Pew Forum on Religion and Public Life found that fifty-four percent of Americans opposed gay marriage.

VOA: special.2010.02.06

Among them teenage pregnancies are rare and often followed by marriage, sometimes at the point of a metaphorical shotgun.

ECONOMIST: Hispanic families

The settlers formed an aristocracy, but it was one which educated indigenous people could join, by talent or by marriage.

ECONOMIST: Liberia

Born on the fringe of the Virginian planter aristocracy, George Washington became a grandee by marriage, proprietor of thousands of acres and master of hundreds of slaves.

ECONOMIST: George Washington