Definition: to avoid telling the truth by not directly answering a question
If telling the truth is to stay on the straight and narrow, then to prevaricate is to take a crooked path. It comes from the Latin word varicare that literally means “to straddle,” derived from varus, meaning “bowlegged,” “bent,” or “knock-kneed.” In Latin, praevaricari was used to mean “to plough (a field) crookedly.” It also had a meaning used in Roman legal contexts that gave rise to our modern one: “to collude”–specifically, for an advocate to conspire with his opponent in order to conceal a crime or secure a particular outcome in a trial. The English word began life with the meaning “to transgress” religious or civil laws and “to go astray” (move crookedly) from rectitude. These meanings are now obsolete in English, but led to the modern meaning “to deviate from the truth” or “to speak equivocally or evasively,” or, to be perfectly blunt about it, “to lie.”
Like many legalistic long Latin-derived words, prevaricate contrasts with the monosyllabic Germanic word lie by adding subtle connotations of evading the truth rather than telling an outright falsehood—a lawyer’s trick.