Definition of "vacuole" []

• A small cavity in the cytoplasm of a cell, bound by a single membrane and containing water, food, or metabolic waste. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In the higher plants, at least, a nucleus occurs embedded in it; a watery liquid holding salts and saccharine substances in solution fills the space called the vacuole, inclosed by the protoplasm."
• "The protoplasm is more or less extensively excavated by fluid spaces, vacuoles; one clearer circular space or vacuole, which is invariably present, appears at intervals, enlarges gradually, and then vanishes abruptly, to reappear after a brief interval; this is called the contractile vacuole (c.v.)."
• "As water evaporates out of the cell, the cell draws more water into the vacuole from other cells deeper inside the tree."