Noun

(uncountable) Inadequacy or incompleteness.

* {{quote-book, year=1963, author=(Margery Allingham), title=(The China Governess)

, chapter=17 citation , passage=The face which emerged was not reassuring. […]. He was not a mongol but there was a deficiency of a sort there, and it was not made more pretty by a latter-day hair cut which involved eccentrically long elf-locks and oiled black curls.}}

(countable) An insufficiency, especially of something essential to health.

* {{quote-magazine, date=2013-08-31, volume=408, issue=8851, magazine=(The Economist)

, title= Promotion and self-promotion , passage=One of academia’s deficiencies is that, though its lecture halls and graduate schools are replete with women, its higher echelons are not. Often, this is seen as a phenomenon specific to the sciences. … In fact, the disparity applies to the whole grove. Another report from 2006, by the American Association of University Professors, found the same ratio in the faculties of arts, humanities and social science, too.}}

(geometry) The amount by which the number of double points on a curve is short of the maximum for curves of the same degree.

(geometry) The codimension of a linear system in the corresponding complete linear system.

Noun

(en noun)

(senseid) A quality of being inadequate; a fault; a disadvantage

* Burke

They see no merit or demerit in any man or any action.

* Sir W. Temple

Secure, unless forfeited by any demerit or offense.

A mark given for bad conduct to a person attending an educational institution or serving in the army.

*2002 , , by G.W.Bush:

*:A few of you have followed in the path of the perfect West Point graduate, Robert E. Lee, who never received a single demerit' in four years. Some of you followed in the path of the imperfect graduate, Ulysses S. Grant, who had his fair share of ' demerits , and said the happiest day of his life was "the day I left West Point." (Laughter.)

That which one merits or deserves, either of good or ill; desert.

* Holland

By many benefits and demerits whereby they obliged their adherents, [they] acquired this reputation.