How to Remember What Duplicity Means

The idea of doubleness is at the core of duplicity. Duplicity comes from a Latin word meaning "double" or "twofold," and its original meaning in English has to do with a kind of deception in which you intentionally hide your true feelings or intentions behind false words or actions. If you are being duplicitous there are two yous: the one you're showing and the one you're hiding. And—key to the idea of duplicity—you're hiding that you in order to make people believe something that's not true.

The word is found in many works of literature, including the Bible:

The integrity of the upright guides them, but the unfaithful are destroyed by their duplicity.
— Proverbs 11:3 (New International Version)

Even when he sat opposite me in the kitchen, talking, he would turn his head a little toward the clock or the stove and look at me from the side, but with frankness and good nature. This trick did not suggest duplicity or secretiveness….
— Willa Cather, My Antonia, 1918

Arch read it at breakfast the day it came out and again that night. He admired its art but was most, affected, and in fact discomfited, by its unblinking inventory of self-seeking and duplicity.
— Tobias Wolff, Old School, 2003

If someone's duplicity has left you feeling like you're seeing double, take heart in the word's etymology. Duplicity comes from a long line of "double" talk, starting with its Latin grandparent duplex, which means "double" or "twofold." As you might expect, duplex is also the parent of another term for doubling it up, duplicate. And of course, the English duplex (which can be a noun meaning "a two-family house" or an adjective meaning "double") comes from the Latin word of the same spelling.