reduction

noun

1. the act of reducing or the state of being reduced.
2. the amount by which something is reduced or diminished.
3. a form produced by reducing; a copy on a smaller scale.
4. Cell Biology. meiosis, especially the first meiotic cell division in which the chromosome number is reduced by half.
5. Chemistry. the process or result of reducing.
6. Movies. the process of making a print of a narrower gauge from a print of a wider gauge: the reduction of 35-mm films to 16-mm for the school market.
7. a village or settlement of Indians in South America established and governed by Spanish Jesuit missionaries.

noun

1. the act or process or an instance of reducing
2. the state or condition of being reduced
3. the amount by which something is reduced
4. a form of an original resulting from a reducing process, such as a copy on a smaller scale
5. a simplified form, such as an orchestral score arranged for piano
6. maths
   1. the process of converting a fraction into its decimal form
   2. the process of dividing out the common factors in the numerator and denominator of a fraction; cancellation

n.

early 15c., “a restoring to a former state; a subjugation” (of a people, etc.), from Middle French reducion (13c., Modern French réduction) and directly from Latin reductionem (nominative reductio) “a leading back, restoration,” noun of action from past participle stem of reducere (see reduce). Meaning “diminution, a lessening” is from 1670s; chemical sense of “reversion to a simpler form” is from 1660s.

n.

1. The act, process, or result of reducing.
2. The amount by which something is lessened or diminished.
3. Restoration of an injured or dislocated part to its normal anatomical relation by surgery or manipulation.
4. The first meiotic division, in which the chromosome number is reduced.reduction division reduction of chromosomes
5. A decrease in positive valence or an increase in negative valence by the gaining of electrons.
6. A reaction in which hydrogen is combined with a compound.
7. A reaction in which oxygen is removed from a compound.

1. The changing of a fraction into a simpler form, especially by dividing the numerator and denominator by a common factor. For example, the fraction 812 can be reduced to 46, which can be further reduced to 23, in each case by dividing both the numerator and denominator by 2.
2. A chemical reaction in which an atom or ion gains electrons, thus undergoing a decrease in valence. If an iron atom having a valence of +3 gains an electron, the valence decreases to +2. Compare oxidation.

Any chemical reaction in which the atoms in a material take on electrons.