40 ILCS 5/20-112

"Survivor's annuity": Payments by a system which are made to the widow or survivors of an employee or participant in the form of a pension or annuity or a lump sum which, under the provisions of the law governing such system, is considered as a widow's or survivor's benefit, or a lump sum which is made in lieu of a pension or annuity which would otherwise be payable to the widow or survivor.