/ Dictionary / Index N nonproficiency: Meaning and Definition of Find definitions for: non•pro•fi•cien•cy Pronunciation: (non"pru-fish'un-sē), [key] — n. absence or lack of proficiency. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. nonprofessional nonprofit Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language