The word "yada" as used in this article is a Hebrew word. It is the Hebrew word for sex, according to Lane.
Lane includes this word in his article because he wants to talk about how important it is for sex to occur only within a marriage. He says that "yada" literally means to "know someone personally." He talks about how open and vulnerable people make themselves to one another when they have sex. This is, to him, one reason why God wants us to have sex only within marriage. Because sex makes us so open to one another, it is a dangerous thing to do when you are not married. It makes you too vulnerable to being hurt by the other person.
"Yada," then, means both "sex" and "to know someone personally." Lane includes this word as a way of emphasizing how personal and powerful sex is and how it must not be engaged in outside of marriage.