not sufficient; lacking in what is necessary or required: an insufficient answer.
deficient in force, quality, or amount; inadequate: insufficient protection.

Origin of insufficient

1350–1400; Middle English < Late Latin insufficient- (stem of insufficiēns). See in-3, sufficient
Related formsin·suf·fi·cient·ly, adverb

Synonyms for insufficient Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for insufficient

Contemporary Examples of insufficient

Historical Examples of insufficient

  • Gotre and other maladies arising from insufficient diet have disappeared.

    In the Heart of Vosges

    Matilda Betham-Edwards

  • But the shock was insufficient to repel the impetus of the charge.

    The Last of the Mohicans

    James Fenimore Cooper

  • The information which Sakemba was able to give us was but little, and insufficient.


    Theodor Hertzka

  • We were only fitted with summer clothing, which was now insufficient protection.

  • Brilliant as might have been his genius, his acquirements necessarily were insufficient.

    Vivian Grey

    Earl of Beaconsfield, Benjamin Disraeli

British Dictionary definitions for insufficient



not sufficient; inadequate or deficient
Derived Formsinsufficiently, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for insufficient

late 14c., from Old French insufficient (14c.), from Latin insufficientem (nominative insufficiens) "insufficient," from in- "not, opposite of" (see in- (1)) + sufficientem (see sufficient). Originally of persons, "inadequate, unable;" of things, from late 15c. Related: Insufficiently.

Online Etymology Dictionary, © 2010 Douglas Harper

insufficient in Medicine




Not sufficient.
Incapable of proper functioning.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.