An adjective, in Latin American Spanish, that refers to an individual as being high on acid or LSD, usually as evidenced by widened pupils, sweating, and talking too much, too loudly, or about obscure subject matter. Referred to in English as tripping.
Friend 1: WOW! Carlos was talking my ear off last night at the festival! What was he on?
Friend 2: Yeah man, he was all acidiao! I couldn't understand what he was even talking about!