Obs. [Cf. DRILL sb.4, a furrow.] A hot-air channel in a green-house, etc.; a flue.
1707. Mortimer, Husb. (1721), II. 191. One part of it may have Trils made under the Floor to convey warmth from the Stoves made on the back side of the House, the better to preserve it from Cold or Dampness.
