/ Dictionary / Index C californium: Meaning and Definition of Find definitions for: cal•i•for•ni•um Pronunciation: (kal"u-fôr'nē-um), [key] — n. Chem. a transuranic element. Symbol: Cf; at. no.: 98. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: californium (Thesaurus) californite caliginous Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language