(Science: ethnology) a tribe of indians which formerly occupied the region of northern illinois, allied in language to the sacs and foxes. Kickback. N. Recoil, of a gun or machine, as in older automobile engines when started by turning a crank. 2. A secret, and usually illegal, payment, by a recipient of money paid for goods or services, to a facilitator of the transaction, of a portion of that money.