Pronunciation: (chek'ôf", -of"), [key]
1. the collection of union dues by employers through compulsory deduction from each worker's wages.
2. a voluntary contribution from one's income tax for a specific purpose, as the public financing of election campaigns, made by checking off the appropriate box on a tax return.
3. Football.audible (def. 2).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.