Lewis & Short

ab-lăquĕo, āvi, ātum, 1, v. a. [laqueus, a hollow], to turn up the earth round a tree, in order to form a trench for water, Cato, R. R. 5, 8, 29; Col. 2, 14, 3; 4, 4, 2; Plin. 17, 19, 31, § 140.