"done with intention, design, or purpose; intended," 1520s, from intention + -al (1) or else from Medieval Latin intentionalis. Intentional fallacy recorded from 1946. Related: Intentionality.
Entries linking to intentional
intention n.
late 14c., entencioun, "purpose, design, aim or object; will, wish, desire, that which is intended," from Old French entencion "intent, purpose, aspiration; will; thought" (12c.), from Latin intentionem (nominative intentio) "a stretching out, straining, exertion, effort; attention," noun of action from intendere "to turn one's attention," literally "to stretch out" (see intend). Also in Middle English "emotion, feelings; heart, mind, mental faculties, understanding."
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).