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n. 1. The lowest or bottom part: the base of a cliff; the base of a lamp. 2. Biology a. The part of a plant or animal organ that is nearest to its point of attachment. b. The point of attachment of such an organ. 3. a. A supporting part or layer; a foundation: a skyscraper built on a base of solid rock. b. A basic or underlying element; infrastructure: the nation's industrial base. 4. The fundamental principle or underlying concept of a system or theory; a basis. 5. A fundamental ingredient; a chief constituent: a paint with an oil base. 6. The fact, observation, or premise from which a reasoning process is begun. 7. a. Games A starting point, safety area, or goal. b. Baseball Any one of the four corners of an infield, marked by a bag or plate, that must be touched by a runner before a run can be scored. 8. a. A center of organization, supply, or activity; a headquarters. b. The portion of a social organization, especially a political party, consisting of the most dedicated or motivated members. 9. a. A fortified center of operations. b. A supply center for a large force of military personnel. 10. A facial cosmetic used to even out the complexion or provide a surface for other makeup; a foundation. 11. Architecture The lowest part of a structure, such as a wall, considered as a separate unit: the base of a column. 12. Heraldry The lower part of a shield. 13. Linguistics A morpheme or morphemes regarded as a form to which affixes or other bases may be added. 14. Mathematics a. The side or face of a geometric figure to which an altitude is or is thought to be drawn. b. The number that is raised to various powers to generate the principal counting units of a number system. The base of the decimal system, for example, is 10. c. The number raised to the logarithm of a designated number in order to produce that designated number; the number at which a chosen logarithmic scale has the value 1. 15. A line used as a reference for measurement or computations. 16. Chemistry a. Any of a class of compounds whose aqueous solutions are characterized by a bitter taste, a slippery feel, the ability to turn litmus blue, and the ability to react with acids to form salts. b. A substance that yields hydroxide ions when dissolved in water. c. A substance that can act as a proton acceptor. d. A substance that can donate a pair of electrons to form a covalent bond. 17. Electronics a. The region in a transistor between the emitter and the collector. b. The electrode attached to this region. 18. One of the nitrogen-containing purines (adenine and guanine) or pyrimidines (cytosine, thymine, and uracil) that occurs attached to the sugar component of DNA or RNA. adj. 1. Forming or serving as a base: a base layer of soil. 2. Situated at or near the base or bottom: a base camp for the mountain climbers. 3. Chemistry Of, relating to, or containing a base. tr.v. based, bas·ing, bas·es Idiom: 1. To form or provide a base for: based the new company in Portland. 2. To find a basis for; establish: based her conclusions on the report; a film based on a best-selling novel. 3. To assign to a base; station: troops based in the Middle East. off base Badly mistaken. [Middle English, from Old French, from Latin basis, from Greek; see gwā- in the Appendix of Indo-European roots.] Synonyms: base1, basis, foundation, ground1, groundwork These nouns all pertain to what underlies and supports. Base is used broadly in both literal and figurative contexts: the wide base of the pyramid; a party seeking to expand its power base. Basis is used in a nonphysical sense: "Healthy scepticism is the basis of all accurate observation" (Arthur Conan Doyle). Foundation often stresses firmness of support for something of relative magnitude: "Our flagrant disregard for the law attacks the foundation of this society" (Peter D. Relic). Ground is used figuratively, especially in the plural, to mean a justifiable reason: grounds for divorce. Groundwork usually has the sense of a necessary preliminary: "It [the Universal Declaration of Human Rights] has laid the groundwork for the world's war crimes tribunals" (Hillary Rodham Clinton). |
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
