Merriam-Webster Collegiate Dictionary - aside

 I. adverb  Date: 14th century  1. to or toward the side stepped ~  2. away from others or into privacy pulled him ~  3. out of the way especially for future use ; away putting ~ savings  4. away from one's thought or consideration jesting ~  II. preposition  Date: 1592 obsolete beyond, past  III. noun  Date: circa 1751  1. an utterance meant to be inaudible to someone; especially an actor's speech heard by the audience but supposedly not by other characters  2. a straying from the theme ; digression