fallible

Errare humanum est. That Latin expression translates into English as "To err is human." Of course, cynics might say that it is also human to deceive. The word fallible simultaneously recognizes both of these human character flaws. In modern usage, it refers to one's ability to err, but it descends from the Latin verb fallere, which means "to deceive." Fallible has been used to describe the potential for error since at least the 15th century. Other descendants of the deceptive fallere in English, all of which actually predate fallible, include fallacy (the earliest, now obsolete, meaning was "guile, trickery"), fault, false, and even fail and failure.