/ Dictionary / Index C countershaft: Meaning and Definition of Find definitions for: coun•ter•shaft Pronunciation: (koun'tur-shaft", -shäft"), [key] — n. Mach. jackshaft (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. countershading countersign Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language