(I) willcomply!; generally, used as a signal of assent UK,1946 Originally used as military communications, often to complement ROGER
“And, Bernie, see that he’s on that plane.” “Willco,” Bernie said. — Ross Russell, TheSound, p. 94, 1961
“Fine, you check the car. I’ll go inside.” Win snapped a salute. “Roger, Wilco.” They split up. Win headed for the lot, Myron for the bar. — Harlan Coben, DropShot, p. 102, 1996