noun

• (skiing) A specialist in aerials, a freestyle skiing discipline.
  "Abramenko, a top aerialist in freestyle skiing, a five-time Olympian and the country’s flag-bearer for the opening ceremony, garnered more attention after the event, when a photograph of his hug with a Russian rival was widely circulated."
• (obsolete) One who operates a flying machine; a balloonist or aviator.
  "1803, A Dictionary of the Wonders of Art, London: T. Hurst, entry “Aeronautics,” p. 32, The balloon, however, having been torn in the lower part, both the cords and netting of the railing of the car broke, the wind again forced away the gentlemen from the tree they were strongly clasping; but with the assistance of a new, though last exertion, the aerialists had an opportunity of leaving the car and balloon, which fell upwards of 200 yards farther."
• (obsolete, rare) A person whose knowledge of agriculture is purely academic and not derived from experience.
  "1825, John Claudius Loudon, An Encyclopaedia of Agriculture, London: Longman, Hurst, Rees, Orme, Brown & Green, Volume 2, p. 1133, Book farmers, the aerialists of Marshal, are those who know agriculture only by reading about it."