I. ˈ ̷ ̷ˌ ̷ ̷ noun
Usage: often attributive
Etymology: check off
: an authorized withholding of union dues, fees, fines, and assessments from the wages of union members and a turning of such withheld money over to the union
II. noun
: designation by a taxpayer of a small amount of income tax to be applied to a special fund (as for financing political campaigns)