1 According to the German psychologist and philosopher Franz Brentano (1838–1917), the property of mental experiences whereby they refer to objects or entities outside themselves: it is impossible to hear without hearing a sound, to believe without believing a statement or a proposition, to hope without hoping for something, to strive without striving for a goal, to feel joy without feeling joyful about something, and so on (these examples are all Brentano's). The concept was introduced by Brentano in 1874 in his book Psychologie vom empirischen Standpunkt (Book II, Chapter I, section 5, pp. 125ff.) to distinguish psychological from physical phenomena, which lack this property of outward-directedness. It is a key concept of phenomenology. See also act psychology.
2 The property of an action that is performed deliberately rather than accidentally or without purpose. [From Latin intentus aim or intent, from intendere to stretch forth or give one's attention to, from in- towards+tendere to stretch]