/ Dictionary / Index S spin quantum number: Meaning and Definition of Find definitions for: spin' quan'tum num"ber Pronunciation: [key] — Physics. Physics. the quantum number that designates the total angular momentum associated with electron spin and has a value of in units of h/2&pgr;. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. spinproof spin resonance Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language