reduction

noun

decrease, make less
process of gaining electrons in a chemical reaction, decreasing oxidation state
music term; arrangement or transcription of an existing score or composition in which complexity is lessened to make analysis, performance, or practice easier or clearer
process of thickening and intensifying the flavor of a liquid mixture such as a soup, sauce, wine, or juice by simmering or boiling
process of rewriting of an expression into a simpler form
the transformation of one computational problem to another, used to show that the second problem is as difficult as the first