Lewis & Short

insūco, āvi, ātum, 1, v. a [1. in-sucus], to soak in, to steep (a favorite word of Columella): lanam vino, Col. 7, 4, 5; 7, 5, 18; 9, 13, 5: panem ex mulso, Cael. Aur. Acut. 3, 8, 77.