/ Dictionary / Index N nuclear fusion: Meaning and Definition of Find definitions for: nu'clear fu'sion Pronunciation: [key] fusion (def. 4). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. nuclear fuel nuclearism Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language