American Heritage Dictionary Entry: blue HOW TO USE THE DICTIONARY To look up an entry in The American Heritage Dictionary of the English Language, use the search window above. For best results, after typing in the word, click on the “Search” button instead of using the “enter” key. Some compound words (like bus rapid transit, dog whistle, or identity theft) don’t appear on the drop-down list when you type them in the search bar. For best results with compound words, place a quotation mark before the compound word in the search window. guide to the dictionary THE USAGE PANEL The Usage Panel is a group of nearly 200 prominent scholars, creative writers, journalists, diplomats, and others in occupations requiring mastery of language. Annual surveys have gauged the acceptability of particular usages and grammatical constructions. The Panelists NEED HELP SOLVING A CROSSWORD PUZZLE? Go to our Crossword Puzzle Solver and type in the letters that you know, and the Solver will produce a list of possible solutions. -- AMERICAN HERITAGE DICTIONARY APP The new American Heritage Dictionary app is now available for iOS and Android. THE AMERICAN HERITAGE DICTIONARY BLOG The articles in our blog examine new words, revised definitions, interesting images from the fifth edition, discussions of usage, and more. OPEN DICTIONARY PROJECT Share your ideas for new words and new meanings of old words! Start Sharing Now! -- See word lists from the best-selling 100 Words Series! Find out more! INTERESTED IN DICTIONARIES? Check out the Dictionary Society of North America at http://www.dictionarysociety.com blue (bl) Share: Tweet n. 1. The hue of that portion of the visible spectrum lying between green and indigo, evoked in the human observer by radiant energy with wavelengths of approximately 420 to 490 nanometers; any of a group of colors that may vary in lightness and saturation, whose hue is that of a clear daytime sky; one of the additive or light primaries; one of the psychological primary hues. 2. a. A pigment or dye imparting this hue. b. Bluing. 3. a. An object having this hue. b. Dress or clothing of this hue: The ushers wore blue. 4. a. A person who wears a blue uniform. b. blues A dress blue uniform, especially that of the US Army. 5. often Blue a. A member of the Union Army in the Civil War. b. The Union Army. 6. A bluefish. 7. Any of various small blue butterflies of the subfamily Polyommatinae. 8. a. The sky. b. The sea. adj. blu·er, blu·est 1. Of the color blue. 2. Bluish or having parts that are blue or bluish, as the blue spruce and the blue whale. 3. Having a gray or purplish color, as from cold or contusion. 4. Wearing blue. 5. Being a trail, as for skiing, marked with a sign having a blue square, indicating an intermediate level of difficulty. 6. Relating to or being a blue state. 7. a. Gloomy; depressed. See Synonyms at depressed. b. Dismal; dreary: a blue day. 8. Puritanical; strict. 9. Aristocratic; patrician. 10. Indecent; risqué: a blue joke; a blue movie. tr. & intr.v. blued, blu·ing, blues To make or become blue. Idioms: blue in the face At the point of extreme exasperation: I argued with them until I was blue in the face. into the blue At a far distance; into the unknown: spontaneously take a trip into the blue. out of the blue 1. From an unexpected or unforeseen source: criticism that came out of the blue. 2. At a completely unexpected time: a long-unseen friend who appeared out of the blue. [Middle English blue, bleu, from Old French bleu, of Germanic origin; see bhel-1 in the Appendix of Indo-European roots.] bluely adv. blueness n. The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved. Indo-European & Semitic Roots Appendices Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices: Indo-European Roots Semitic Roots The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots. 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