A figure of speech in which two essentially unlike things are compared, often in a phrase introduced by like or as, as in "How like the winter hath my absence been” or "So are you to my thoughts as food to life” (Shakespeare).
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.