# deficiency

Pronunciation: say "di-FISH-uhn-see" /dɪˈfɪʃənsi/

## Noun

1. A shortage or insufficiency of something, especially of a nutrient or other element essential to health.
   - Simple: A lack of something a person needs, especially for good health.
   - _Blood tests revealed a serious iron deficiency that explained her constant fatigue._
   - _Children raised on that limited diet often develop vitamin deficiencies._
2. The condition of being inadequate or incomplete; a falling short of what is needed or expected.
   - Simple: The state of not being good enough or complete.
   - _The audit exposed deficiency in the company's record-keeping practices._
   - _Critics pointed to general deficiency in the proposal's reasoning._
3. In geometry, the amount by which a curve's number of double points falls short of the maximum possible for curves of the same degree.
   - Simple: In math, how many fewer crossing points a curve has than the most it could have.
   - _The deficiency tells us how many double points the curve lacks relative to others of its degree._
   - _Computing the deficiency requires comparing the curve's double points with the theoretical maximum._
4. In geometry, the codimension of a linear system within the corresponding complete linear system: how many dimensions it falls short of the full system.
   - Simple: In math, the number of dimensions a smaller family of shapes is missing compared with the full family it sits inside.
   - _When the deficiency is zero, the linear system is complete._
   - _Algebraic geometers compute the deficiency to measure how far a system sits inside its complete counterpart._

## Origin

Formed from "deficient" plus the suffix "-cy," comparable to Latin "dēficientia."

Source: DictionaryAI, https://dictionaryai.com/define/deficiency (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).