What is Actio?

Legal Definition
Actio is a term in rhetoric that means the delivery that is given to a speech. Hand gestures, voice variation, speaker to audience eye contact, and an engaging manner are all needed for an effective actio.
-- Wikipedia
Legal Definition
Lat In the civil law. An action or suit; a right or cause of action. It should be noted that this term means both the proceeding to enforce a right in a court and the right itself which is sought to be enforced.
See also
-- Black's Law Dictionary
Legal Definition
An action at law; a right to sue.
-- Ballentine's Law Dictionary