Decrescendo a. & adv. : With decreasing volume of sound; -- a direction to performers, either written upon the staff (abbreviated Dec., or Decresc.), or indicated by the sign.

Example:
what are the 2 ways to draw both a crescendo and Decrescendo in music?

Taxonomy
decrescendo, Merriam-Webster Online Dictionary, Dictionary, webster, scen, Word Games, musical passage, Webster Online Dictionary with audio pronunciations, thesaurus, glossary, english, language, ESL, 1de, kr, shen, Inflected, Etymology.

Defination from the web:
decrescendo from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... decrescendo. 2 entries found. 1decrescendo (noun) 2decrescendo (adverb or adjective) Main Entry: 1de·cre·scen·do. Pronunciation: ˌdā-krə-ˈshen-(ˌ)dō ...