/ Dictionary / Index C csk.: Meaning and Definition of Find definitions for: csk. Pronunciation: [key] cask. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. CSF C.S.O. Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language