advertent

You may be thinking that advertent should mean "intentional." After all, inadvertent means "unintentional." Take away the negative prefix in- and you're left with that word's opposite, right? If this is your line of thought, you're not entirely off base; the two words (which both entered English in the 17th century and derive from Latin advertere, meaning "to turn the mind or attention") are in fact closely linked. But inadvertent has another, older meaning: "inattentive" or "not focusing the mind on a matter." The established meaning of advertent falls opposite that older sense of inadvertent. Does this mean that advertent never means "intentional"? Not exactly. We have seen some evidence of this use, but it's not yet well enough established to be entered in our dictionaries.