Spray drain

(Agric.) a drain made by laying under earth the sprays or small branches of trees, which keep passages open.

See also: Spray

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
After a simple demonstration, employees learn to spray drains with a liquid that works its way into drain nooks and crannies, turning into a semi-gel for high contact time.